diff --git a/net/common/rpc-service.c b/net/common/rpc-service.c
index 53290e3..e5fd054 100644
--- a/net/common/rpc-service.c
+++ b/net/common/rpc-service.c
@@ -300,6 +300,10 @@ ccnet_start_rpc(CcnetSession *session)
                                      ccnet_rpc_get_descendants_groups,
                                      "get_descendants_groups",
                                      searpc_signature_objlist__int());
+    searpc_server_register_function ("ccnet-threaded-rpcserver",
+                                     ccnet_rpc_get_groups_members,
+                                     "get_groups_members",
+                                     searpc_signature_objlist__string());
 
     searpc_server_register_function ("ccnet-threaded-rpcserver",
                                      ccnet_rpc_create_org,
@@ -1674,4 +1678,16 @@ ccnet_rpc_get_primary_id (const char *email, GError **error)
     return ccnet_user_manager_get_primary_id (user_mgr, email);
 }
 
+GList *
+ccnet_rpc_get_groups_members (const char *group_ids, GError **error)
+{
+    if (!group_ids || g_strcmp0(group_ids, "") == 0) {
+        g_set_error (error, CCNET_DOMAIN, CCNET_ERR_INTERNAL, "Bad arguments");
+        return NULL;
+    }
+    CcnetGroupManager *group_mgr = ((CcnetServerSession *)session)->group_mgr;
+
+    return ccnet_group_manager_get_groups_members (group_mgr, group_ids, error);
+}
+
 #endif  /* CCNET_SERVER */
diff --git a/net/common/rpc-service.h b/net/common/rpc-service.h
index 6608df9..334cbf7 100644
--- a/net/common/rpc-service.h
+++ b/net/common/rpc-service.h
@@ -347,4 +347,7 @@ ccnet_rpc_login_relay (const char *relay_id, const char *email,
 int
 ccnet_rpc_logout_relay (const char *relay_id, GError **error);
 
+GList *
+ccnet_rpc_get_groups_members (const char *group_ids, GError **error);
+
 #endif /* RPC_SERVICE_H */
diff --git a/net/common/session.h b/net/common/session.h
index 06ad27e..6238ef1 100644
--- a/net/common/session.h
+++ b/net/common/session.h
@@ -13,6 +13,8 @@
 
 #include <glib.h>
 #include <glib/gstdio.h>
+#include <jansson.h>
+
 #include "ccnet-session-base.h"
 
 #include "processor.h"
diff --git a/net/server/group-mgr.c b/net/server/group-mgr.c
index 8ed0d0c..4a136d7 100644
--- a/net/server/group-mgr.c
+++ b/net/server/group-mgr.c
@@ -1312,3 +1312,64 @@ ccnet_group_manager_search_groups (CcnetGroupManager *mgr,
 
     return g_list_reverse (ret);
 }
+
+static gboolean
+get_groups_members_cb (CcnetDBRow *row, void *data)
+{
+    GList **users = data;
+    const char *user = ccnet_db_row_get_column_text (row, 0);
+
+    char *user_l = g_ascii_strdown (user, -1);
+    CcnetGroupUser *group_user = g_object_new (CCNET_TYPE_GROUP_USER,
+                                               "user_name", user_l,
+                                               NULL);
+    g_free (user_l);
+    *users = g_list_append(*users, group_user);
+
+    return TRUE;
+}
+
+/* group_ids is json format: "[id1, id2, id3, ...]" */
+GList *
+ccnet_group_manager_get_groups_members (CcnetGroupManager *mgr, const char *group_ids,
+                                        GError **error)
+{
+    CcnetDB *db = mgr->priv->db;
+    GList *ret = NULL;
+    GString *sql = g_string_new ("");
+    int i, group_id;
+    json_t *j_array = NULL, *j_obj;
+    json_error_t j_error;
+
+    g_string_printf (sql, "SELECT DISTINCT user_name FROM GroupUser WHERE group_id IN (");
+    j_array = json_loadb (group_ids, strlen(group_ids), 0, &j_error);
+    if (!j_array) {
+        g_set_error (error, CCNET_DOMAIN, 0, "Bad args.");
+        g_string_free (sql, TRUE);
+        return NULL;
+    }
+    size_t id_num = json_array_size (j_array);
+
+    for (i = 0; i < id_num; i++) {
+        j_obj = json_array_get (j_array, i);
+        group_id = json_integer_value (j_obj);
+        if (group_id <= 0) {
+            g_set_error (error, CCNET_DOMAIN, 0, "Bad args.");
+            g_string_free (sql, TRUE);
+            json_decref (j_array);
+            return NULL;
+        }
+        g_string_append_printf (sql, "%d", group_id);
+        if (i + 1 < id_num)
+            g_string_append_printf (sql, ",");
+    }
+    g_string_append_printf (sql, ")");
+    json_decref (j_array);
+
+    if (ccnet_db_statement_foreach_row (db, sql->str, get_groups_members_cb, &ret, 0) < 0)
+        ccnet_warning("Failed to get groups members for group [%s].\n", group_ids);
+
+    g_string_free (sql, TRUE);
+
+    return ret;
+}
diff --git a/net/server/group-mgr.h b/net/server/group-mgr.h
index c857ac1..f03f90f 100644
--- a/net/server/group-mgr.h
+++ b/net/server/group-mgr.h
@@ -138,5 +138,8 @@ ccnet_group_manager_get_descendants_groups (CcnetGroupManager *mgr, int group_id
 GList *
 ccnet_group_manager_get_ancestor_groups (CcnetGroupManager *mgr, int group_id);
 
+GList *
+ccnet_group_manager_get_groups_members (CcnetGroupManager *mgr, const char *group_ids,
+                                        GError **error);
 #endif /* GROUP_MGR_H */
 
diff --git a/python/ccnet/rpc.py b/python/ccnet/rpc.py
index fedf29e..fe87b90 100644
--- a/python/ccnet/rpc.py
+++ b/python/ccnet/rpc.py
@@ -446,3 +446,7 @@ class CcnetThreadedRpcClient(RpcClientBase):
     @searpc_func("string", ["string"])
     def get_primary_id(self, email):
         pass
+
+    @searpc_func("objlist", ["string"])
+    def get_groups_members(self, group_ids):
+        pass