diff --git a/cyberbrain-vsc/src/interactions.ts b/cyberbrain-vsc/src/interactions.ts
new file mode 100644
index 00000000..cc8d7243
--- /dev/null
+++ b/cyberbrain-vsc/src/interactions.ts
@@ -0,0 +1,86 @@
+import {
+  window,
+  Range,
+  Position,
+  workspace,
+  TextEditor,
+  OverviewRulerLane,
+  TextEditorDecorationType
+} from "vscode";
+
+enum Behavior {
+  Hover = "Hover",
+  Unhover = "Unhover"
+}
+
+/**
+ * `Interactions` is used to implement the interaction behaviors from users when they interact with cyberbrain webpages.
+ * To add an interation, post message to Vscode when a user's interaction behavior is detected, parse the message with rpc server,
+ * define relative interactions logic in the `Interactions`, and then call `Interactions.excute` to excute it.
+ * Current Interaction Behaviors includes:
+ * 1. Highlight the line of the node in the editor when hovering the mouse on any node. Cancel the highlight when the node is unhovered.
+ **/
+export class Interactions {
+  private decorateType: TextEditorDecorationType | undefined;
+
+  getDecorationType(): TextEditorDecorationType {
+    return window.createTextEditorDecorationType({
+      isWholeLine: true,
+      overviewRulerLane: OverviewRulerLane.Right,
+      light: {
+        // this color will be used in light color themes
+        backgroundColor: "#fcf29f",
+        overviewRulerColor: "#fcf29f"
+      },
+      dark: {
+        // this color will be used in dark color themes
+        backgroundColor: "#264F78",
+        overviewRulerColor: "#264F78"
+      }
+    });
+  }
+
+  /**
+   * Highlight the given line on the Editor.
+   * @param lineno  the highlighted line's number.
+   * @param relativePath  the relative path of the file which the highlighted line belongs to.
+   */
+  highlightLineOnEditor(lineno: number, relativePath: string) {
+    const nodeEditor = window.visibleTextEditors.filter(
+      editor => editor.document.uri.fsPath.indexOf(relativePath) !== -1
+    )[0];
+    if (nodeEditor) {
+      // create a decoration type everytime since it will be disposed when unhovering the node
+      this.decorateType = this.getDecorationType();
+      let lineRange = [
+        {
+          range: new Range(
+            new Position(lineno - 1, 0),
+            new Position(lineno - 1, 100)
+          )
+        }
+      ];
+      nodeEditor.setDecorations(this.decorateType, lineRange);
+    }
+  }
+
+  execute(interactionConfig: { type: String; info?: any }) {
+    switch (interactionConfig.type) {
+      case Behavior.Hover:
+        if (interactionConfig.info?.hasOwnProperty("lineno")) {
+          this.highlightLineOnEditor(
+            interactionConfig.info["lineno"],
+            interactionConfig.info["relativePath"]
+          );
+        }
+        break;
+      case Behavior.Unhover:
+        if (this.decorateType) {
+          this.decorateType.dispose();
+        }
+        break;
+      default:
+        break;
+    }
+  }
+}
diff --git a/cyberbrain-vsc/src/rpc_server.ts b/cyberbrain-vsc/src/rpc_server.ts
index d50af7f9..b19ee0f6 100644
--- a/cyberbrain-vsc/src/rpc_server.ts
+++ b/cyberbrain-vsc/src/rpc_server.ts
@@ -4,6 +4,7 @@ import * as bodyParser from "body-parser";
 import { openTraceGraph } from "./webview";
 import { isTestMode } from "./utils";
 import { decode } from "@msgpack/msgpack";
+import { Interactions } from "./interactions";
 
 let cl = console.log;
 
@@ -14,11 +15,13 @@ export class RpcServer {
   private server: express.Express;
   private readonly context: vscode.ExtensionContext;
   private readonly listeningPort = 1989; // TODO: Make it configurable.
-  
+  private interactions: Interactions;
+
   constructor(context: vscode.ExtensionContext) {
     this.context = context;
     this.server = express();
     this.server.use(bodyParser.raw({ limit: "10GB" }));
+    this.interactions = new Interactions();
 
     this.server.post("/frame", (req, res) => {
       cl("get message");
@@ -28,8 +31,11 @@ export class RpcServer {
       // Sends data to the trace graph in webview.
       let webviewPanel = openTraceGraph(this.context);
       webviewPanel.webview.onDidReceiveMessage(
-        (message: string) => {
-          if (message === "Webview ready") {
+        (message: {
+          command: string;
+          interactionConfig?: { type: string; info?: any };
+        }) => {
+          if (message.command === "Webview ready") {
             webviewPanel.webview.postMessage(decode(req.body));
 
             // If under test, don't open the devtools window because it will cover the trace graph.
@@ -39,6 +45,15 @@ export class RpcServer {
               );
             }
           }
+          if (message.command === "Interaction behavior") {
+            try {
+              if (message.interactionConfig) {
+                this.interactions.execute(message.interactionConfig);
+              }
+            } catch (error) {
+              cl("Failed to execute the interation behavior: ", error);
+            }
+          }
         },
         undefined,
         this.context.subscriptions
diff --git a/cyberbrain-vsc/src/trace_graph.js b/cyberbrain-vsc/src/trace_graph.js
index 9aea88c4..938e98c7 100644
--- a/cyberbrain-vsc/src/trace_graph.js
+++ b/cyberbrain-vsc/src/trace_graph.js
@@ -294,11 +294,29 @@ class TraceGraph {
         return;
       }
       this.hoveredNodeId = node.id;
+
+      // highlight the current hoverd node's line on the editor
+      vscode.postMessage({
+        command: "Interaction behavior",
+        interactionConfig: {
+          type: "Hover",
+          info: { lineno: node.lineno, relativePath: node.filename }
+        }
+      });
+
       // TODO: show values of all local variables at this point.
       displayValueInConsole(node);
     });
 
     this.network.on("blurNode", event => {
+      // unhighlight the current hoverd node's line on the editor
+      vscode.postMessage({
+        command: "Interaction behavior",
+        interactionConfig: {
+          type: "Unhover"
+        }
+      });
+
       this.hoveredNodeId = undefined;
     });
 
@@ -338,6 +356,7 @@ class TraceGraph {
       level: this.traceData.linenoMapping.get(event.lineno),
       lineno: event.lineno,
       label: buildLabelText(event),
+      filename: this.traceData.frameMetadata.filename,
       target: event.target,
       // "value" is a reserved property, use "runtimeValue" instead.
       runtimeValue: event.value,
diff --git a/cyberbrain-vsc/src/webview.ts b/cyberbrain-vsc/src/webview.ts
index 86c84b5d..8158a223 100644
--- a/cyberbrain-vsc/src/webview.ts
+++ b/cyberbrain-vsc/src/webview.ts
@@ -103,7 +103,7 @@ export function openTraceGraph(
     <div id='vis'>
     <script>
         const vscode = acquireVsCodeApi();
-        vscode.postMessage("Webview ready");
+        vscode.postMessage({command:"Webview ready"});
     </script>
 </body>
 </html>`;