diff --git a/core/src/main/scala/org/apache/spark/deploy/JsonProtocol.scala b/core/src/main/scala/org/apache/spark/deploy/JsonProtocol.scala
index f697892aacc83..0a5399a5ba52a 100644
--- a/core/src/main/scala/org/apache/spark/deploy/JsonProtocol.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/JsonProtocol.scala
@@ -188,7 +188,7 @@ private[deploy] object JsonProtocol {
    * Export the [[MasterStateResponse]] to a Json object. A [[MasterStateResponse]] consists the
    * information of a master node.
    *
-   * @return a Json object containing the following fields:
+   * @return a Json object containing the following fields if `field` is None:
    *         `url` the url of the master node
    *         `workers` a list of Json objects of [[WorkerInfo]] of the workers allocated to the
    *         master
@@ -208,24 +208,63 @@ private[deploy] object JsonProtocol {
    *         `completeddrivers` a list of Json objects of [[DriverInfo]] of the completed drivers
    *         of the master
    *         `status` status of the master,
-   *         see [[org.apache.spark.deploy.master.RecoveryState.MasterState]]
+   *         see [[org.apache.spark.deploy.master.RecoveryState.MasterState]].
+   *         If `field` is not None, the Json object will contain the matched field.
+   *         If `field` doesn't match, the Json object `(field -> "")` is returned.
    */
-  def writeMasterState(obj: MasterStateResponse): JObject = {
+  def writeMasterState(obj: MasterStateResponse, field: Option[String] = None): JObject = {
     val aliveWorkers = obj.workers.filter(_.isAlive())
-    ("url" -> obj.uri) ~
-    ("workers" -> obj.workers.toList.map(writeWorkerInfo)) ~
-    ("aliveworkers" -> aliveWorkers.length) ~
-    ("cores" -> aliveWorkers.map(_.cores).sum) ~
-    ("coresused" -> aliveWorkers.map(_.coresUsed).sum) ~
-    ("memory" -> aliveWorkers.map(_.memory).sum) ~
-    ("memoryused" -> aliveWorkers.map(_.memoryUsed).sum) ~
-    ("resources" -> aliveWorkers.map(_.resourcesInfo).toList.map(writeResourcesInfo)) ~
-    ("resourcesused" -> aliveWorkers.map(_.resourcesInfoUsed).toList.map(writeResourcesInfo)) ~
-    ("activeapps" -> obj.activeApps.toList.map(writeApplicationInfo)) ~
-    ("completedapps" -> obj.completedApps.toList.map(writeApplicationInfo)) ~
-    ("activedrivers" -> obj.activeDrivers.toList.map(writeDriverInfo)) ~
-    ("completeddrivers" -> obj.completedDrivers.toList.map(writeDriverInfo)) ~
-    ("status" -> obj.status.toString)
+    field match {
+      case None =>
+        ("url" -> obj.uri) ~
+        ("workers" -> obj.workers.toList.map (writeWorkerInfo) ) ~
+        ("aliveworkers" -> aliveWorkers.length) ~
+        ("cores" -> aliveWorkers.map (_.cores).sum) ~
+        ("coresused" -> aliveWorkers.map (_.coresUsed).sum) ~
+        ("memory" -> aliveWorkers.map (_.memory).sum) ~
+        ("memoryused" -> aliveWorkers.map (_.memoryUsed).sum) ~
+        ("resources" -> aliveWorkers.map (_.resourcesInfo).toList.map (writeResourcesInfo) ) ~
+        ("resourcesused" ->
+          aliveWorkers.map (_.resourcesInfoUsed).toList.map (writeResourcesInfo) ) ~
+        ("activeapps" -> obj.activeApps.toList.map (writeApplicationInfo) ) ~
+        ("completedapps" -> obj.completedApps.toList.map (writeApplicationInfo) ) ~
+        ("activedrivers" -> obj.activeDrivers.toList.map (writeDriverInfo) ) ~
+        ("completeddrivers" -> obj.completedDrivers.toList.map (writeDriverInfo) ) ~
+        ("status" -> obj.status.toString)
+      case Some(field) =>
+        field match {
+          case "url" =>
+            ("url" -> obj.uri)
+          case "workers" =>
+            ("workers" -> obj.workers.toList.map (writeWorkerInfo) )
+          case "aliveworkers" =>
+            ("aliveworkers" -> aliveWorkers.length)
+          case "cores" =>
+            ("cores" -> aliveWorkers.map (_.cores).sum)
+          case "coresused" =>
+            ("coresused" -> aliveWorkers.map (_.coresUsed).sum)
+          case "memory" =>
+            ("memory" -> aliveWorkers.map (_.memory).sum)
+          case "memoryused" =>
+            ("memoryused" -> aliveWorkers.map (_.memoryUsed).sum)
+          case "resources" =>
+            ("resources" -> aliveWorkers.map (_.resourcesInfo).toList.map (writeResourcesInfo) )
+          case "resourcesused" =>
+            ("resourcesused" ->
+              aliveWorkers.map (_.resourcesInfoUsed).toList.map (writeResourcesInfo) )
+          case "activeapps" =>
+            ("activeapps" -> obj.activeApps.toList.map (writeApplicationInfo) )
+          case "completedapps" =>
+            ("completedapps" -> obj.completedApps.toList.map (writeApplicationInfo) )
+          case "activedrivers" =>
+            ("activedrivers" -> obj.activeDrivers.toList.map (writeDriverInfo) )
+          case "completeddrivers" =>
+            ("completeddrivers" -> obj.completedDrivers.toList.map (writeDriverInfo) )
+          case "status" =>
+            ("status" -> obj.status.toString)
+          case field => (field -> "")
+        }
+    }
   }
 
   /**
diff --git a/core/src/main/scala/org/apache/spark/deploy/master/ui/MasterPage.scala b/core/src/main/scala/org/apache/spark/deploy/master/ui/MasterPage.scala
index 02c488656b848..cc4370ad02e06 100644
--- a/core/src/main/scala/org/apache/spark/deploy/master/ui/MasterPage.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/master/ui/MasterPage.scala
@@ -32,13 +32,17 @@ import org.apache.spark.util.Utils
 
 private[ui] class MasterPage(parent: MasterWebUI) extends WebUIPage("") {
   private val master = parent.masterEndpointRef
+  private val jsonFieldPattern = "/json/([a-zA-Z]+).*".r
 
   def getMasterState: MasterStateResponse = {
     master.askSync[MasterStateResponse](RequestMasterState)
   }
 
   override def renderJson(request: HttpServletRequest): JValue = {
-    JsonProtocol.writeMasterState(getMasterState)
+    jsonFieldPattern.findFirstMatchIn(request.getRequestURI()) match {
+      case None => JsonProtocol.writeMasterState(getMasterState)
+      case Some(m) => JsonProtocol.writeMasterState(getMasterState, Some(m.group(1)))
+    }
   }
 
   def handleAppKillRequest(request: HttpServletRequest): Unit = {
diff --git a/core/src/test/scala/org/apache/spark/deploy/JsonProtocolSuite.scala b/core/src/test/scala/org/apache/spark/deploy/JsonProtocolSuite.scala
index 5e62323770e1b..4a6ace6facdea 100644
--- a/core/src/test/scala/org/apache/spark/deploy/JsonProtocolSuite.scala
+++ b/core/src/test/scala/org/apache/spark/deploy/JsonProtocolSuite.scala
@@ -76,6 +76,22 @@ class JsonProtocolSuite extends SparkFunSuite with JsonTestUtils {
     assertValidDataInJson(output, JsonMethods.parse(JsonConstants.masterStateJsonStr))
   }
 
+  test("SPARK-45474: filtered writeMasterState") {
+    val workers = Array(createWorkerInfo(), createWorkerInfo())
+    val activeApps = Array(createAppInfo())
+    val completedApps = Array.empty[ApplicationInfo]
+    val activeDrivers = Array(createDriverInfo())
+    val completedDrivers = Array(createDriverInfo())
+    val stateResponse = new MasterStateResponse(
+      "host", 8080, None, workers, activeApps, completedApps,
+      activeDrivers, completedDrivers, RecoveryState.ALIVE)
+    val output = JsonProtocol.writeMasterState(stateResponse, Some("activedrivers"))
+    assertValidJson(output)
+
+    val expected = """{"activedrivers":[%s]}""".format(JsonConstants.driverInfoJsonStr).stripMargin
+    assertValidDataInJson(output, JsonMethods.parse(expected))
+  }
+
   test("writeWorkerState") {
     val executors = List[ExecutorRunner]()
     val finishedExecutors = List[ExecutorRunner](createExecutorRunner(123, true),