diff --git a/onnxscript/function_libs/torch_lib/ops/core.py b/onnxscript/function_libs/torch_lib/ops/core.py
index 4a338ecc1d..555806e299 100644
--- a/onnxscript/function_libs/torch_lib/ops/core.py
+++ b/onnxscript/function_libs/torch_lib/ops/core.py
@@ -6718,10 +6718,47 @@ def aten_unflatten(self: TReal, dim: INT64, sizes: INT64):
     return op.Reshape(self, final_shape)
 
 
-def aten_unfold(self: TensorType, dimension: int, size: int, step: int) -> TensorType:
+@torch_op("aten::unfold", trace_only=True)
+def aten_unfold(self: TTensor, dimension: int, size: int, step: int) -> TTensor:
     """unfold(Tensor(a) self, int dimension, int size, int step) -> Tensor(a)"""
 
-    raise NotImplementedError()
+    self_rank = len(self.shape)
+    if self_rank == 0:
+        result = op.Unsqueeze(self, 0)
+    else:
+        dim_size = self.shape[dimension]
+        target_end = (dim_size - size) // step + 1
+        if target_end > 1:  # the rank of final reuslt will be self_rank + 1
+            self_rank = self_rank + 1
+        # perm need to be list[int], so have to be generated in trace_only mode
+        perm = list(range(self_rank))
+        # from [0,1,2,3,4] -> [0,1,3,4,2] when dimension=1
+        perm.append(perm.pop(dimension + 1))
+        result = _aten_unfold_onnx(self, dimension, size, step, target_end, perm)
+    return result
+
+
+@torch_op("aten::unfold", private=True)
+def _aten_unfold_onnx(
+    self: TTensor, dim: int, size: int, step: int, target_end: int, perm: Sequence[int]
+) -> TTensor:
+    dims = op.Reshape(op.Constant(value_int=dim), op.Constant(value_ints=[-1]))
+    # FIXME: the dtype for this function cannot work, default to float
+    seq_result = op.SequenceEmpty()
+    i = op.Constant(value_ints=[0])
+    cond = i < target_end
+    while cond:  # because for loop cannot work here, so use while loop
+        starts = i * step  # starts is [0, step, step*2, step*3, ...]
+        ends = starts + size  # ends is [0+size, step+size, step*2+size, step*3+size, ...]
+        slice_result = op.Slice(self, starts, ends, dims)
+        # sequence only support float32
+        slice_result_float32 = op.Cast(slice_result, to=FLOAT.dtype)
+        seq_result = op.SequenceInsert(seq_result, slice_result_float32)
+        i = i + 1
+        cond = i < target_end
+    concat_result = op.ConcatFromSequence(seq_result, axis=dim, new_axis=1)
+    result = op.Transpose(concat_result, perm=perm)
+    return op.CastLike(result, self)
 
 
 def aten_unfold_backward(
diff --git a/onnxscript/tests/function_libs/torch_lib/ops_test_data.py b/onnxscript/tests/function_libs/torch_lib/ops_test_data.py
index 4c7b027984..db7cd97da5 100644
--- a/onnxscript/tests/function_libs/torch_lib/ops_test_data.py
+++ b/onnxscript/tests/function_libs/torch_lib/ops_test_data.py
@@ -430,7 +430,7 @@ def _where_input_wrangler(
     TorchLibOpInfo("acos", core_ops.aten_acos),
     TorchLibOpInfo("acosh", core_ops.aten_acosh),
     TorchLibOpInfo("add", core_ops.aten_add, tolerance={torch.float16: (1e-3, 1e-3)}),
-    TorchLibOpInfo("addbmm", core_ops.aten_addbmm),
+    TorchLibOpInfo("addbmm", core_ops.aten_addbmm, tolerance={torch.float32: (2e-5, 2e-5)}),
     TorchLibOpInfo("addcdiv", core_ops.aten_addcdiv),
     TorchLibOpInfo("addcmul", core_ops.aten_addcmul, tolerance={torch.float16: (4e-3, 3e-3)}),
     TorchLibOpInfo("addmm", core_ops.aten_addmm),
@@ -1166,6 +1166,7 @@ def _where_input_wrangler(
         matcher=lambda sample: any(dim == 0 for dim in sample.input.shape),
         reason="fixme: Logic not implemented for size 0 inputs in op.Reshape",
     ),
+    TorchLibOpInfo("unfold", core_ops.aten_unfold, trace_only=True),
     TorchLibOpInfo("unsqueeze", core_ops.aten_unsqueeze),
     TorchLibOpInfo("view", core_ops.aten_view),
     TorchLibOpInfo("view_as", core_ops.aten_view_as),