diff --git a/pkg/cloudprovider/providers/azure/azure_vmsets.go b/pkg/cloudprovider/providers/azure/azure_vmsets.go
new file mode 100644
index 00000000000..dd5cc308dcd
--- /dev/null
+++ b/pkg/cloudprovider/providers/azure/azure_vmsets.go
@@ -0,0 +1,59 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package azure
+
+import (
+	"github.com/Azure/azure-sdk-for-go/arm/network"
+
+	"k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/kubernetes/pkg/cloudprovider"
+)
+
+// VMSet defines functions all vmsets (including scale set and availabitlity
+// set) should be implemented.
+type VMSet interface {
+	// GetInstanceIDByNodeName gets the cloud provider ID by node name.
+	// It must return ("", cloudprovider.InstanceNotFound) if the instance does
+	// not exist or is no longer running.
+	GetInstanceIDByNodeName(name string) (string, error)
+	// GetInstanceTypeByNodeName gets the instance type by node name.
+	GetInstanceTypeByNodeName(name string) (string, error)
+	// GetIPByNodeName gets machine IP by node name.
+	GetIPByNodeName(name, vmSetName string) (string, error)
+	// GetPrimaryInterface gets machine primary network interface by node name and vmSet.
+	GetPrimaryInterface(nodeName, vmSetName string) (network.Interface, error)
+	// GetNodeNameByProviderID gets the node name by provider ID.
+	GetNodeNameByProviderID(providerID string) (types.NodeName, error)
+
+	// GetZoneByNodeName gets cloudprovider.Zone by node name.
+	GetZoneByNodeName(name string) (cloudprovider.Zone, error)
+
+	// GetPrimaryVMSetName returns the VM set name depending on the configured vmType.
+	// It returns config.PrimaryScaleSetName for vmss and config.PrimaryAvailabilitySetName for standard vmType.
+	GetPrimaryVMSetName() string
+	// GetVMSetNames selects all possible availability sets or scale sets
+	// (depending vmType configured) for service load balancer, if the service has
+	// no loadbalancer mode annotaion returns the primary VMSet. If service annotation
+	// for loadbalancer exists then return the eligible VMSet.
+	GetVMSetNames(service *v1.Service, nodes []*v1.Node) (availabilitySetNames *[]string, err error)
+	// EnsureHostsInPool ensures the given Node's primary IP configurations are
+	// participating in the specified LoadBalancer Backend Pool.
+	EnsureHostsInPool(serviceName string, nodes []*v1.Node, backendPoolID string, vmSetName string) error
+	// EnsureBackendPoolDeleted ensures the loadBalancer backendAddressPools deleted from the specified vmSet.
+	EnsureBackendPoolDeleted(poolID, vmSetName string) error
+}