diff --git a/spark-on-angel/mllib/src/main/scala/com/tencent/angel/spark/ml/automl/feature/PipelineBuilder.scala b/spark-on-angel/mllib/src/main/scala/com/tencent/angel/spark/ml/automl/feature/PipelineBuilder.scala
new file mode 100644
index 000000000..8bddd7240
--- /dev/null
+++ b/spark-on-angel/mllib/src/main/scala/com/tencent/angel/spark/ml/automl/feature/PipelineBuilder.scala
@@ -0,0 +1,30 @@
+/*
+ * Tencent is pleased to support the open source community by making Angel available.
+ *
+ * Copyright (C) 2017-2018 THL A29 Limited, a Tencent company. All rights reserved.
+ *
+ * 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
+ *
+ * https://opensource.org/licenses/Apache-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 com.tencent.angel.spark.ml.automl.feature
+
+import org.apache.spark.ml.PipelineStage
+import org.apache.spark.ml.Transformer
+
+object PipelineBuilder {
+
+  def declareFields(pipeline: Array[PipelineStage]): Unit = {
+
+  }
+
+}
diff --git a/spark-on-angel/mllib/src/main/scala/com/tencent/angel/spark/ml/automl/feature/TransformerWrapper.scala b/spark-on-angel/mllib/src/main/scala/com/tencent/angel/spark/ml/automl/feature/TransformerWrapper.scala
new file mode 100644
index 000000000..a3d09ad26
--- /dev/null
+++ b/spark-on-angel/mllib/src/main/scala/com/tencent/angel/spark/ml/automl/feature/TransformerWrapper.scala
@@ -0,0 +1,56 @@
+/*
+ * Tencent is pleased to support the open source community by making Angel available.
+ *
+ * Copyright (C) 2017-2018 THL A29 Limited, a Tencent company. All rights reserved.
+ *
+ * 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
+ *
+ * https://opensource.org/licenses/Apache-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 com.tencent.angel.spark.ml.automl.feature
+
+import org.apache.spark.ml.Transformer
+
+import scala.collection.mutable.ArrayBuffer
+
+abstract class TransformerWrapper {
+
+  val transformer: Transformer
+  var parentTransformer: Transformer
+
+  val requiredInputCols: Array[String]
+  val requiredOutputCols: Array[String]
+
+  val inputCols: ArrayBuffer[String]
+  val outputCols: ArrayBuffer[String]
+
+  var parentCols: Array[String]
+
+  def getTransformer: Transformer = transformer
+
+  def setParent(parent: Transformer) = parentTransformer = parent
+
+  def hasInputCol: Boolean
+
+  def hasOutputCol: Boolean
+
+  def getInputCols: Array[String] = inputCols.toArray
+
+  def getOutputCols: Array[String] = outputCols.toArray
+
+  def addInputCol(col: String): Unit = inputCols += col
+
+  def addOutputCol(col: String): Unit = outputCols += col
+
+  def setParentCols: Array[String] = parentCols
+
+}
diff --git a/spark-on-angel/mllib/src/main/scala/com/tencent/angel/spark/ml/automl/feature/preprocess/SamplerWrapper.scala b/spark-on-angel/mllib/src/main/scala/com/tencent/angel/spark/ml/automl/feature/preprocess/SamplerWrapper.scala
new file mode 100644
index 000000000..016a807f0
--- /dev/null
+++ b/spark-on-angel/mllib/src/main/scala/com/tencent/angel/spark/ml/automl/feature/preprocess/SamplerWrapper.scala
@@ -0,0 +1,43 @@
+/*
+ * Tencent is pleased to support the open source community by making Angel available.
+ *
+ * Copyright (C) 2017-2018 THL A29 Limited, a Tencent company. All rights reserved.
+ *
+ * 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
+ *
+ * https://opensource.org/licenses/Apache-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 com.tencent.angel.spark.ml.automl.feature.preprocess
+
+import com.tencent.angel.spark.ml.automl.feature.TransformerWrapper
+import org.apache.spark.ml.Transformer
+
+import scala.collection.mutable.ArrayBuffer
+
+class SamplerWrapper(fraction: Double) extends TransformerWrapper {
+
+  override val transformer: Transformer = new Sampler(fraction)
+  override var parentTransformer: Transformer = _
+
+  override val requiredInputCols: Array[String] = null
+  override val requiredOutputCols: Array[String] = null
+
+  override val inputCols: ArrayBuffer[String] = new ArrayBuffer[String]()
+  override val outputCols: ArrayBuffer[String] = new ArrayBuffer[String]()
+
+  override var parentCols: Array[String] = _
+
+  override def hasInputCol: Boolean = true
+
+  override def hasOutputCol: Boolean = false
+
+}
diff --git a/spark-on-angel/mllib/src/main/scala/com/tencent/angel/spark/ml/automl/feature/preprocess/StopWordsRemoverWrapper.scala b/spark-on-angel/mllib/src/main/scala/com/tencent/angel/spark/ml/automl/feature/preprocess/StopWordsRemoverWrapper.scala
new file mode 100644
index 000000000..19fecc442
--- /dev/null
+++ b/spark-on-angel/mllib/src/main/scala/com/tencent/angel/spark/ml/automl/feature/preprocess/StopWordsRemoverWrapper.scala
@@ -0,0 +1,42 @@
+/*
+ * Tencent is pleased to support the open source community by making Angel available.
+ *
+ * Copyright (C) 2017-2018 THL A29 Limited, a Tencent company. All rights reserved.
+ *
+ * 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
+ *
+ * https://opensource.org/licenses/Apache-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 com.tencent.angel.spark.ml.automl.feature.preprocess
+
+import com.tencent.angel.spark.ml.automl.feature.TransformerWrapper
+import org.apache.spark.ml.Transformer
+
+import scala.collection.mutable.ArrayBuffer
+import org.apache.spark.ml.feature.StopWordsRemover
+
+class StopWordsRemoverWrapper extends TransformerWrapper {
+
+  override val transformer: Transformer = new StopWordsRemover()
+  override var parentTransformer: Transformer = _
+
+  override val requiredInputCols: Array[String] = Array("words")
+  override val requiredOutputCols: Array[String] = Array("filteredwords")
+
+  override val inputCols: ArrayBuffer[String] = _
+  override val outputCols: ArrayBuffer[String] = _
+
+  override var parentCols: Array[String] = _
+
+  override def hasInputCol: Boolean = true
+
+  override def hasOutputCol: Boolean = true
+}
diff --git a/spark-on-angel/mllib/src/main/scala/com/tencent/angel/spark/ml/automl/feature/preprocess/TokenizerWrapper.scala b/spark-on-angel/mllib/src/main/scala/com/tencent/angel/spark/ml/automl/feature/preprocess/TokenizerWrapper.scala
new file mode 100644
index 000000000..63357e382
--- /dev/null
+++ b/spark-on-angel/mllib/src/main/scala/com/tencent/angel/spark/ml/automl/feature/preprocess/TokenizerWrapper.scala
@@ -0,0 +1,43 @@
+/*
+ * Tencent is pleased to support the open source community by making Angel available.
+ *
+ * Copyright (C) 2017-2018 THL A29 Limited, a Tencent company. All rights reserved.
+ *
+ * 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
+ *
+ * https://opensource.org/licenses/Apache-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 com.tencent.angel.spark.ml.automl.feature.preprocess
+
+import com.tencent.angel.spark.ml.automl.feature.TransformerWrapper
+import org.apache.spark.ml.Transformer
+
+import scala.collection.mutable.ArrayBuffer
+import org.apache.spark.ml.feature.Tokenizer
+
+class TokenizerWrapper extends TransformerWrapper {
+
+  override val transformer: Transformer = new Tokenizer()
+  override var parentTransformer: Transformer = _
+
+  override val requiredInputCols: Array[String] = Array("sentence")
+  override val requiredOutputCols: Array[String] = Array("words")
+
+  override val inputCols: ArrayBuffer[String] = _
+  override val outputCols: ArrayBuffer[String] = _
+  
+  override var parentCols: Array[String] = _
+
+  override def hasInputCol: Boolean = true
+
+  override def hasOutputCol: Boolean = true
+}