diff --git a/paddle/gserver/layers/SequenceSliceLayer.cpp b/paddle/gserver/layers/SequenceSliceLayer.cpp
index 5d72d373047fd6232e97139433b9cd17779a4a03..aab44c464666d4741ea4352dbfa1852d176f516e 100644
--- a/paddle/gserver/layers/SequenceSliceLayer.cpp
+++ b/paddle/gserver/layers/SequenceSliceLayer.cpp
@@ -130,6 +130,8 @@ void SequenceSliceLayer::calSelectedRows(const MatrixPtr starts,
   CHECK(starts || ends) << "At least one of the start or end indices "
                         << "should be given.";
 
+  bool hasSubseq = getInput(0).hasSubseq();
+
   outSeqStartPos_.resize(1, 0);
   outSubSeqStartPos_.resize(1, 0);
   selectedRows_.clear();
@@ -151,14 +153,13 @@ void SequenceSliceLayer::calSelectedRows(const MatrixPtr starts,
         int seqLen = endPos - begPos + 1;
         CHECK_GT(seqLen, 0U);
         for (int m = begPos; m <= endPos; ++m) selectedRows_.push_back(m);
-        inputSeqInfoVec_.size() > 1
+        hasSubseq
             ? outSubSeqStartPos_.push_back(outSubSeqStartPos_.back() + seqLen)
             : outSeqStartPos_.push_back(outSeqStartPos_.back() + seqLen);
       }
       rowIdx++;
     }
-    if (inputSeqInfoVec_.size() > 1)
-      outSeqStartPos_.push_back(outSubSeqStartPos_.back());
+    if (hasSubseq) outSeqStartPos_.push_back(outSubSeqStartPos_.back());
   }
 
   if (useGpu_) {
@@ -175,7 +176,7 @@ void SequenceSliceLayer::calSelectedRows(const MatrixPtr starts,
   output_.sequenceStartPositions->copyFrom(
       outSeqStartPos_.data(), outSeqStartPos_.size(), false);
 
-  if (inputSeqInfoVec_.size() > 1) {
+  if (hasSubseq) {
     ICpuGpuVector::resizeOrCreate(
         output_.subSequenceStartPositions, outSubSeqStartPos_.size(), false);
     output_.subSequenceStartPositions->copyFrom(
@@ -203,10 +204,11 @@ void SequenceSliceLayer::forward(PassType passType) {
   } else
     copySliceIdsToCpu();
 
-  // calculate the selected row indices in a batch,
-  // and build the output sequence information.
-  calSelectedRows(startIdsOnCpu_ ? startIdsOnCpu_ : nullptr,
-                  endIdsOnCpu_ ? endIdsOnCpu_ : nullptr);
+  /*
+   * calculate the selected row indices in a batch, and build the output
+   * sequence information.
+   */
+  calSelectedRows(startIdsOnCpu_, endIdsOnCpu_);
 
   resetOutput(selectedRows_.size(), getSize());
 
diff --git a/paddle/gserver/tests/test_SeqSliceLayerGrad.cpp b/paddle/gserver/tests/test_SeqSliceLayerGrad.cpp
index d560ca650bc5b156de280a2a0d698b67eb032907..e1d4ae16176433b898ba88dd60550e44b4fe37be 100644
--- a/paddle/gserver/tests/test_SeqSliceLayerGrad.cpp
+++ b/paddle/gserver/tests/test_SeqSliceLayerGrad.cpp
@@ -30,6 +30,8 @@ const int MAX_SEQ_NUM = 17;
 const int MAX_SEQ_LEN = 23;
 const int MAX_BEAM_SIZE = 13;
 
+const size_t SEED = (size_t)(time(NULL));
+
 vector<real> randSampling(real range, int n) {
   CHECK_GE(range, n);
   vector<real> num(range);
@@ -46,7 +48,7 @@ void genSeqInfo(vector<int>& seqStartPos, vector<int>& subSeqStartPos) {
   seqStartPos.resize(1, 0);
   subSeqStartPos.resize(1, 0);
 
-  srand((size_t)(time(NULL)));
+  srand(SEED);
   int seqNum = 1 + (rand() % MAX_SEQ_NUM);
   for (int i = 0; i < seqNum; ++i) {
     int subSeqNum = 1 + (rand() % MAX_SEQ_NUM);