diff --git a/specification/datafactory/resource-manager/Microsoft.DataFactory/2017-09-01-preview/datafactory.json b/specification/datafactory/resource-manager/Microsoft.DataFactory/2017-09-01-preview/datafactory.json
index c7c83e64ffd0..14712908d0d6 100644
--- a/specification/datafactory/resource-manager/Microsoft.DataFactory/2017-09-01-preview/datafactory.json
+++ b/specification/datafactory/resource-manager/Microsoft.DataFactory/2017-09-01-preview/datafactory.json
@@ -1770,6 +1770,48 @@
         }
       }
     },
+    "/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/Microsoft.DataFactory/factories/{factoryName}/cancelpipelinerun/{runId}": {
+      "post": {
+        "operationId": "Factories_CancelPipelineRun",
+        "x-ms-examples": {
+          "Factories_CancelPipelineRun": {
+            "$ref": "./examples/Factories_CancelPipelineRun.json"
+          }
+        },
+        "description": "Cancel a pipeline run by its run ID.",
+        "tags": [
+          "pipelineruns"
+        ],
+        "parameters": [
+          {
+            "$ref": "#/parameters/subscriptionId"
+          },
+          {
+            "$ref": "#/parameters/resourceGroupName"
+          },
+          {
+            "$ref": "#/parameters/factoryName"
+          },
+          {
+            "$ref": "#/parameters/runId"
+          },
+          {
+            "$ref": "#/parameters/api-version"
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "Pipeline run has been canceled successfully. "
+          },
+          "default": {
+            "description": "An error response received from the Azure Data Factory service.",
+            "schema": {
+              "$ref": "#/definitions/ErrorResponse"
+            }
+          }
+        }
+      }
+    },
     "/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/Microsoft.DataFactory/factories/{factoryName}/triggers": {
       "get": {
         "tags": [
diff --git a/specification/datafactory/resource-manager/Microsoft.DataFactory/2017-09-01-preview/examples/Factories_CancelPipelineRun.json b/specification/datafactory/resource-manager/Microsoft.DataFactory/2017-09-01-preview/examples/Factories_CancelPipelineRun.json
new file mode 100644
index 000000000000..5b03267619e1
--- /dev/null
+++ b/specification/datafactory/resource-manager/Microsoft.DataFactory/2017-09-01-preview/examples/Factories_CancelPipelineRun.json
@@ -0,0 +1,21 @@
+{
+  "parameters": {
+    "subscriptionId": "12345678-1234-1234-12345678abc",
+    "resourceGroupName": "exampleResourceGroup",
+    "factoryName": "exampleFactoryName",
+    "runId": "39692ed9-c722-4d33-b8e1-1f4a9deac57f",
+    "api-version": "2017-09-01-preview"
+  },
+  "responses": {
+    "200": {
+      "headers": {
+        "Date": "Mon, 02 Oct 2017 17:27:33 GMT",
+        "x-ms-request-id": "fd3867ea-c65c-470d-a17b-d83c8864cf90",
+        "X-Content-Type-Options": "nosniff",
+        "x-ms-ratelimit-remaining-subscription-writes": "1113",
+        "x-ms-correlation-request-id": "d0b45db5-c155-4991-95d9-22655c72c986"
+      },
+      "body": null
+    }
+  }
+}
\ No newline at end of file