diff --git a/frontend/src/components/comments-list.js b/frontend/src/components/comments-list.js
new file mode 100644
index 0000000000..d774c8adad
--- /dev/null
+++ b/frontend/src/components/comments-list.js
@@ -0,0 +1,215 @@
+import React from 'react';
+import PropTypes from 'prop-types';
+import moment from 'moment';
+import { processor } from '@seafile/seafile-editor/dist/utils/seafile-markdown2html';
+import { Button, Dropdown, DropdownToggle, DropdownMenu, DropdownItem } from 'reactstrap';
+import { gettext } from '../utils/constants';
+import { seafileAPI } from '../utils/seafile-api';
+import '../css/comments-list.css';
+
+const { repoID, filePath } = window.app.pageOptions;
+const { username } = window.app.userInfo;
+
+const CommentsListPropTypes = {
+  toggleCommentsList: PropTypes.func.isRequired
+};
+
+class CommentsList extends React.Component {
+
+  constructor(props) {
+    super(props);
+    this.state = {
+      commentsList: [],
+      showResolvedComment: true,
+    };
+  }
+
+  toggleResolvedComment = () => {
+    this.setState({
+      showResolvedComment: !this.state.showResolvedComment
+    });
+  }
+
+  listComments = () => {
+    seafileAPI.listComments(repoID, filePath).then((res) => {
+      this.setState({
+        commentsList: res.data.comments
+      });
+    });
+  }
+
+  handleCommentChange = (event) => {
+    this.setState({
+      comment: event.target.value,
+    });
+  }
+
+  submitComment = () => {
+    let comment = this.refs.commentTextarea.value;
+    if (comment.trim()) {
+      seafileAPI.postComment(repoID, filePath, comment).then(() => {
+        this.listComments();
+      });
+    }
+    this.refs.commentTextarea.value = '';
+  }
+
+  resolveComment = (event) => {
+    seafileAPI.updateComment(repoID, event.target.id, 'true').then(() => {
+      this.listComments();
+    });
+  }
+
+  deleteComment = (event) => {
+    seafileAPI.deleteComment(repoID, event.target.id).then(() => {
+      this.listComments();
+    });
+  }
+
+  componentDidMount() {
+    this.listComments();
+  }
+
+  render() {
+    return (
+      <div className="seafile-comment">
+        <div className="seafile-comment-title">
+          <div onClick={this.props.toggleCommentsList} className={'seafile-comment-title-close'}>
+            <i className={'fa fa-times-circle'}/>
+          </div>
+          <div className={'seafile-comment-title-text'}>{gettext('comments')}</div>
+        </div>
+        <div className="seafile-comment-toggle-resolved">
+          <div className={'seafile-comment-title-text'}>{gettext('Show resolved comments')}</div>
+          <div className={'seafile-comment-title-toggle d-flex'}>
+            <label className="custom-switch" id="toggle-resolved-comments">
+              <input type="checkbox" name="option" className="custom-switch-input"
+                onChange={this.toggleResolvedComment}
+                checked={this.state.showResolvedComment && 'checked'}
+              />
+              <span className="custom-switch-indicator"></span>
+            </label>
+          </div>
+        </div>
+        <ul className={'seafile-comment-list'}>
+          {this.state.commentsList.length > 0 &&
+            this.state.commentsList.map((item, index = 0, arr) => {
+              let oldTime = (new Date(item.created_at)).getTime();
+              let time = moment(oldTime).format('YYYY-MM-DD HH:mm');
+              return (
+                <React.Fragment key={item.id}>
+                  <CommentItem
+                    item={item} time={time}
+                    deleteComment={this.deleteComment}
+                    resolveComment={this.resolveComment}
+                    showResolvedComment={this.state.showResolvedComment}
+                  />
+                </React.Fragment>
+              );
+            })
+          }
+          {(this.state.commentsList.length == 0 ) &&
+            <li className="comment-vacant">{gettext('no_comment_yet')}</li>}
+        </ul>
+        <div className="seafile-comment-footer">
+            <textarea
+              className="add-comment-input" ref="commentTextarea"
+              placeholder={gettext('Add a comment.')}
+              clos="100" rows="3" warp="virtual"></textarea>
+            <Button
+              className="submit-comment" color="success"
+              size="sm" onClick={this.submitComment} >
+              {gettext('submit')}</Button>
+        </div>
+      </div>
+    );
+  }
+}
+
+CommentsList.propTypes = CommentsListPropTypes;
+
+
+const commentItemPropTypes = {
+  time: PropTypes.string.isRequired,
+  item: PropTypes.object.isRequired,
+  deleteComment: PropTypes.func.isRequired,
+  resolveComment: PropTypes.func.isRequired,
+  showResolvedComment: PropTypes.bool.isRequired,
+};
+
+class CommentItem extends React.Component {
+
+  constructor(props) {
+    super(props);
+    this.state = {
+      dropdownOpen: false,
+      html: '',
+    };
+  }
+
+  toggleDropDownMenu = () => {
+    this.setState({
+      dropdownOpen: !this.state.dropdownOpen,
+    });
+  }
+
+  convertComment = (mdFile) => {
+    processor.process(mdFile).then(
+      (result) => {
+        let html = String(result);
+        this.setState({
+          html: html
+        });
+      }
+    );
+  }
+
+  componentWillMount() {
+    this.convertComment(this.props.item.comment);
+  }
+
+  componentWillReceiveProps(nextProps) {
+    this.convertComment(nextProps.item.comment);
+  }
+
+  render() {
+    const item = this.props.item;
+    if (item.resolved && !this.props.showResolvedComment) {
+      return null;
+    }
+    return (
+      <li className={item.resolved ? 'seafile-comment-item seafile-comment-item-resolved'
+        : 'seafile-comment-item'} id={item.id}>
+        <div className="seafile-comment-info">
+          <img className="avatar" src={item.avatar_url} alt=""/>
+          <div className="reviewer-info">
+            <div className="reviewer-name">{item.user_name}</div>
+            <div className="review-time">{this.props.time}</div>
+          </div>
+          <Dropdown isOpen={this.state.dropdownOpen} size="sm"
+            className="seafile-comment-dropdown" toggle={this.toggleDropDownMenu}>
+            <DropdownToggle className="seafile-comment-dropdown-btn">
+              <i className="fas fa-ellipsis-v"></i>
+            </DropdownToggle>
+            <DropdownMenu>
+              {
+                (item.user_email === username) &&
+                <DropdownItem onClick={this.props.deleteComment} className="delete-comment"
+                  id={item.id}>{gettext('Delete')}</DropdownItem>}
+              {
+                !item.resolved &&
+                <DropdownItem onClick={this.props.resolveComment} className="seafile-comment-resolved"
+                  id={item.id}>{gettext('Mark as resolved')}</DropdownItem>
+              }
+            </DropdownMenu>
+          </Dropdown>
+        </div>
+        <div className="seafile-comment-content" dangerouslySetInnerHTML={{ __html: this.state.html }}></div>
+      </li>
+    );
+  }
+}
+
+CommentItem.propTypes = commentItemPropTypes;
+
+export default CommentsList;
diff --git a/frontend/src/css/comments-list.css b/frontend/src/css/comments-list.css
new file mode 100644
index 0000000000..6c9ba562c5
--- /dev/null
+++ b/frontend/src/css/comments-list.css
@@ -0,0 +1,118 @@
+.seafile-comment {
+  border-left: 1px solid #e6e6dd;
+  display: flex;
+  flex-direction: column;
+}
+.seafile-comment-title {
+  border-bottom: 1px solid #e5e5e5;
+  min-height: 3em;
+  line-height: 3em;
+  padding: 0 1em;
+  display: flex;
+  background-color: #fafaf9;
+}
+.seafile-comment-title .seafile-comment-title-text {
+  width: 100%;
+  text-align: center;
+  font-weight: 700;
+}
+.seafile-comment-title .seafile-comment-title-close {
+  color: #b9b9b9;
+}
+.seafile-comment-title .seafile-comment-title-close:hover {
+  color: #888;
+}
+.seafile-comment-toggle-resolved {
+  margin-top: 45px;
+  border-bottom: 1px solid #e5e5e5;
+  padding: 5px 10px;
+  display: flex;
+  position: absolute;
+  background-color: #fff;
+  justify-content: space-between;
+  width: 29%;
+}
+.seafile-comment-list {
+  height: calc(100% - 40px);
+  margin-top: 30px;
+  overflow-y: auto;
+  margin-bottom: 0;
+}
+.seafile-comment-list .comment-vacant {
+  padding: 1em;
+  text-align: center;
+}
+.seafile-comment-item {
+  overflow-y: hidden;
+  padding: 15px 10px;
+  margin-bottom: 0;
+}
+.seafile-comment-item .seafile-comment-info {
+  padding-bottom: 0.5em;
+  height: 3em;
+  display: flex;
+  justify-content: flex-start;
+}
+.seafile-comment-item .seafile-comment-info .reviewer-info {
+  padding-left: 10px;
+}
+.seafile-comment-item .seafile-comment-info .review-time {
+  font-size: 10px;
+  color: #777;
+}
+.seafile-comment-item .seafile-comment-info .seafile-comment-dropdown {
+  margin-left: auto;
+}
+.seafile-comment-item .seafile-comment-info .seafile-comment-dropdown button {
+  border: none;
+  box-shadow: none;
+  background-color: #fff;
+}
+.seafile-comment-item .seafile-comment-info .seafile-comment-dropdown .seafile-comment-dropdown-btn {
+  color: #999;
+  background-color: transparent;
+}
+.seafile-comment-item .seafile-comment-info .seafile-comment-dropdown:hover .seafile-comment-dropdown-btn {
+  color: #555;
+}
+.seafile-comment-item .seafile-comment-info .seafile-comment-dropdown button:hover,
+.seafile-comment-item .seafile-comment-info .seafile-comment-dropdown button:focus {
+  border: none;
+  box-shadow: none;
+  background-color: #eee;
+}
+.seafile-comment-item .seafile-comment-content {
+  margin-left: 42px;
+}
+.seafile-comment-item .seafile-comment-content ol,
+.seafile-comment-item .seafile-comment-content ul,
+.seafile-comment-item .seafile-comment-content li {
+  margin-left: 10px;
+}
+.seafile-comment-item .seafile-comment-content table,
+.seafile-comment-item .seafile-comment-content th,
+.seafile-comment-item .seafile-comment-content td {
+  border: 1px solid #333;
+}
+.seafile-comment-item-resolved {
+  background-color: #e6ffed;
+}
+.seafile-comment-footer {
+  background-color: #fafaf9;
+  padding: 10px 10px 0;
+  border-top: 1px solid #e5e5e5;
+  display: flex;
+  flex-direction: column;
+  min-height: 150px;
+}
+.seafile-comment-footer .add-comment-input {
+  border: 1px solid #e6e6dd;
+  padding: 5px;
+  width: 23em;
+  min-height: 90px;
+}
+.seafile-comment-footer .submit-comment {
+  margin-top: 5px;
+  width: 60px;
+  height: 28px;
+}
diff --git a/frontend/src/css/view-file-text.css b/frontend/src/css/view-file-text.css
index fc860dee6d..000c7a4992 100644
--- a/frontend/src/css/view-file-text.css
+++ b/frontend/src/css/view-file-text.css
@@ -80,4 +80,20 @@
 
 .file-internal-link {
   color: #585858;
-}
\ No newline at end of file
+}
+
+.txt-file-view-body .txt-view-comment {
+  background: #fff;
+  display: flex;
+  height: 100%;
+} 
+
+.txt-file-view-body .txt-view-comment .ReactCodeMirror {
+  width: 70%;
+  margin: 5px 20px;
+  overflow-y: auto;
+}
+
+.txt-file-view-body .txt-view-comment .seafile-comment {
+  width: 30%;
+}
diff --git a/frontend/src/view-file-text.js b/frontend/src/view-file-text.js
index e0de470eed..97f5e44b1d 100644
--- a/frontend/src/view-file-text.js
+++ b/frontend/src/view-file-text.js
@@ -9,6 +9,7 @@ import { seafileAPI } from './utils/seafile-api';
 import { Utils } from './utils/utils';
 import { serviceURL, gettext, mediaUrl } from './utils/constants';
 import InternalLinkDialog from './components/dialog/internal-link-dialog';
+import CommentsList from './components/comments-list';
 import 'codemirror/lib/codemirror.css';
 import 'codemirror/mode/javascript/javascript';
 import 'codemirror/mode/css/css';
@@ -87,6 +88,9 @@ class ViewFileText extends React.Component {
       case 'download':
         window.location.href = serviceURL + '/lib/' + repoID + '/file/' + filePath +'?dl=1';
         break;
+      case 'comment':
+        this.toggleCommentsList();
+        break;
     }
   }
 
@@ -128,19 +132,23 @@ class ViewFileText extends React.Component {
             onMouseDown={() => this.handleMouseDown('download')}
             icon={'fa fa-download'}
           />
-          {/*
-            <IconButton
-              id={'commentButton'}
-              text={gettext('Comment')}
-              onMouseDown={() => this.handleMouseDown('comment')}
-              icon={'sf-btn-group-btn op-icon sf2-icon-msgs sf-btn-group-btn-last'}
-            />
-          */}
+          <IconButton
+            id={'commentButton'}
+            text={gettext('Comment')}
+            onMouseDown={() => this.handleMouseDown('comment')}
+            icon={'fa fa-comment'}
+          />
         </ButtonGroup>
       </div>
     );
   }
 
+  toggleCommentsList = () => {
+    this.setState({
+      showCommentsList: !this.state.showCommentsList
+    });
+  }
+
   toggleStar = () => {
     if (this.state.star) {
       seafileAPI.unStarFile(repoID, filePath).then((res) => {
@@ -190,13 +198,16 @@ class ViewFileText extends React.Component {
           {this.renderToolbar()}
         </div>
         <div className="txt-file-view-body d-flex">
-          {this.fileEncode()}
-          <div className={'txt-view'}>
+          {!this.state.showCommentsList && this.fileEncode()}
+          <div className={this.state.showCommentsList ? 'txt-view-comment' : 'txt-view'}>
             <CodeMirror
               ref="code-mirror-editor"
               value={fileContent}
               options={options}
             />
+            { this.state.showCommentsList &&
+              <CommentsList toggleCommentsList={this.toggleCommentsList}/>
+            }
           </div>
         </div>
       </div>