diff --git a/include/core/tensor.h b/include/core/tensor.h
index 422355e9..1edc950a 100644
--- a/include/core/tensor.h
+++ b/include/core/tensor.h
@@ -56,16 +56,16 @@ class TensorObj : public TensorBaseObj {
     Tensor clone() const {
         auto obj = make_ref<TensorObj>(*this);
         obj->freeData();
-        obj->inputOf.clear();
-        obj->outputOf.reset();
+        obj->targets.clear();
+        obj->source.reset();
         return obj;
     }
     Tensor clone(Runtime runtime) const {
         auto obj = make_ref<TensorObj>(*this);
         obj->runtime = runtime;
         obj->freeData();
-        obj->inputOf.clear();
-        obj->outputOf.reset();
+        obj->targets.clear();
+        obj->source.reset();
         if (hasData()) {
             obj->dataMalloc();
             obj->copyData(this);
diff --git a/include/core/tensor_base.h b/include/core/tensor_base.h
index af2b97c3..09286a63 100644
--- a/include/core/tensor_base.h
+++ b/include/core/tensor_base.h
@@ -19,8 +19,8 @@ class TensorBaseObj : public Object {
     int dim;
 
     DataType dtype;
-    vector<WRef<OperatorObj>> inputOf;
-    WRef<OperatorObj> outputOf;
+    vector<WRef<OperatorObj>> targets;
+    WRef<OperatorObj> source;
     Blob data;
     Runtime runtime;
 
@@ -46,10 +46,13 @@ class TensorBaseObj : public Object {
     DataType getDType() const { return dtype; }
     Runtime getRuntime() const { return runtime; }
 
-    void addInputOf(const Operator &op) { inputOf.emplace_back(op); }
-    void setOutputOf(const Operator &op) { outputOf = op; }
-    OpVec getInputOf() { return wrefs_to_refs(inputOf); }
-    Operator getOutputOf() { return outputOf.lock(); }
+    void addInputOf(const Operator &op) { targets.emplace_back(op); }
+    void setOutputOf(const Operator &op) { source = op; }
+
+    bool hasTarget() const { return !targets.empty(); }
+
+    OpVec getInputOf() const { return wrefs_to_refs(targets); }
+    Operator getOutputOf() const { return source.lock(); }
     //     std::pair<Operator *, int> getOutputOfWithIndex();
 
     //     bool setScalar(VType val) {
diff --git a/pyinfinitensor/src/pyinfinitensor/onnx.py b/pyinfinitensor/src/pyinfinitensor/onnx.py
index 6b3e394c..f8fd662c 100644
--- a/pyinfinitensor/src/pyinfinitensor/onnx.py
+++ b/pyinfinitensor/src/pyinfinitensor/onnx.py
@@ -334,7 +334,6 @@ def from_onnx(
 
     inputs: Dict[str, backend.Tensor] = {}
     for name, obj in tensors.items():
-        print("{}: {}".format(name, obj))
         tensor = data.get(name)
         if tensor == None:
             if any(input.name == name for input in model.graph.input):
@@ -382,6 +381,12 @@ def to_onnx(graph: backend.GraphHandler, name: str) -> ModelProto:
 
         def push_output(self, name: str, tensor: backend.Tensor) -> str:
             self.names[tensor] = name
+            if not tensor.has_target():
+                shape = tensor.shape()
+                dtype = backend.tensor_dtype(tensor)
+                value_info = make_tensor_value_info(name, dtype, shape)
+                check_value_info(value_info)
+                self.outputs.append(value_info)
             return name
 
         def push_input(self, tensor: backend.Tensor) -> str:
diff --git a/src/core/tensor.cc b/src/core/tensor.cc
index 89294a8e..5f04e114 100644
--- a/src/core/tensor.cc
+++ b/src/core/tensor.cc
@@ -18,13 +18,13 @@ string TensorObj::toString() const {
                  std::to_string(fuid) + ", shape " + vecToString(shape) +
                  ", dtype " + dtype.toString();
     vector<UidBaseType> inputOfGuid;
-    for (const auto &op : inputOf)
+    for (const auto &op : targets)
         inputOfGuid.emplace_back(op.lock()->getGuid());
-    if (auto o = outputOf.lock())
-        ret += ", outputOf " + std::to_string(o->getGuid());
+    if (auto o = source.lock())
+        ret += ", source " + std::to_string(o->getGuid());
     else
-        ret += ", outputOf None";
-    ret += ", inputOf " + vecToString(inputOfGuid);
+        ret += ", source None";
+    ret += ", targets " + vecToString(inputOfGuid);
     return ret;
 }
 
diff --git a/src/ffi/ffi_infinitensor.cc b/src/ffi/ffi_infinitensor.cc
index 2be4971b..53e1376c 100644
--- a/src/ffi/ffi_infinitensor.cc
+++ b/src/ffi/ffi_infinitensor.cc
@@ -147,6 +147,7 @@ void init_graph_builder(py::module &m) {
     py::class_<TensorObj, std::shared_ptr<TensorObj>>(m, "Tensor")
         .def("shape", &TensorObj::getDims, policy::move)
         .def("cloneFloats", &TensorObj::cloneFloats, policy::move)
+        .def("has_target", &TensorObj::hasTarget, policy::automatic)
         .def("src", &TensorObj::getOutputOf, policy::move);
     py::class_<OperatorObj, std::shared_ptr<OperatorObj>>(m, "Operator")
         .def("op_type", &OperatorObj::getOpType, policy::automatic)