diff --git a/paconvert/attribute_mapping.json b/paconvert/attribute_mapping.json
index 96d4603b8..5ad404223 100644
--- a/paconvert/attribute_mapping.json
+++ b/paconvert/attribute_mapping.json
@@ -102,18 +102,33 @@
   "torch.bfloat16": {
     "Matcher": "ChangePrefixMatcher"
   },
+  "torch.bfloat16.itemsize": {
+    "Matcher": "ChangePrefixMatcher"
+  },
   "torch.bool": {
     "Matcher": "ChangePrefixMatcher"
   },
+  "torch.bool.itemsize": {
+    "Matcher": "ChangePrefixMatcher"
+  },
   "torch.cfloat": {
     "Matcher": "ChangePrefixMatcher"
   },
+  "torch.cfloat.itemsize": {
+    "Matcher": "ChangePrefixMatcher"
+  },
   "torch.complex128": {
     "Matcher": "ChangePrefixMatcher"
   },
+  "torch.complex128.itemsize": {
+    "Matcher": "ChangePrefixMatcher"
+  },
   "torch.complex64": {
     "Matcher": "ChangePrefixMatcher"
   },
+  "torch.complex64.itemsize": {
+    "Matcher": "ChangePrefixMatcher"
+  },
   "torch.distributed.ReduceOp.MAX": {
     "Matcher": "ChangePrefixMatcher"
   },
@@ -136,6 +151,9 @@
   "torch.double": {
     "Matcher": "ChangePrefixMatcher"
   },
+  "torch.double.itemsize": {
+    "Matcher": "ChangePrefixMatcher"
+  },
   "torch.dtype": {
     "Matcher": "ChangePrefixMatcher"
   },
@@ -145,33 +163,60 @@
   "torch.float16": {
     "Matcher": "ChangePrefixMatcher"
   },
+  "torch.float16.itemsize": {
+    "Matcher": "ChangePrefixMatcher"
+  },
   "torch.float32": {
     "Matcher": "ChangePrefixMatcher"
   },
+  "torch.float32.itemsize": {
+    "Matcher": "ChangePrefixMatcher"
+  },
   "torch.float64": {
     "Matcher": "ChangePrefixMatcher"
   },
+  "torch.float64.itemsize": {
+    "Matcher": "ChangePrefixMatcher"
+  },
   "torch.float8_e4m3fn": {
     "Matcher": "ChangePrefixMatcher"
   },
+  "torch.float8_e4m3fn.itemsize": {
+    "Matcher": "ChangePrefixMatcher"
+  },
   "torch.inf": {
     "Matcher": "ChangePrefixMatcher"
   },
   "torch.int16": {
     "Matcher": "ChangePrefixMatcher"
   },
+  "torch.int16.itemsize": {
+    "Matcher": "ChangePrefixMatcher"
+  },
   "torch.int32": {
     "Matcher": "ChangePrefixMatcher"
   },
+  "torch.int32.itemsize": {
+    "Matcher": "ChangePrefixMatcher"
+  },
   "torch.int64": {
     "Matcher": "ChangePrefixMatcher"
   },
+  "torch.int64.itemsize": {
+    "Matcher": "ChangePrefixMatcher"
+  },
   "torch.int8": {
     "Matcher": "ChangePrefixMatcher"
   },
+  "torch.int8.itemsize": {
+    "Matcher": "ChangePrefixMatcher"
+  },
   "torch.long": {
     "Matcher": "ChangePrefixMatcher"
   },
+  "torch.long.itemsize": {
+    "Matcher": "ChangePrefixMatcher"
+  },
   "torch.nan": {
     "Matcher": "ChangePrefixMatcher"
   },
@@ -187,6 +232,9 @@
   "torch.uint8": {
     "Matcher": "ChangePrefixMatcher"
   },
+  "torch.uint8.itemsize": {
+    "Matcher": "ChangePrefixMatcher"
+  },
   "torch.utils.cpp_extension.BuildExtension.with_options": {
     "Matcher": "ChangePrefixMatcher"
   },
diff --git a/tests/test_dtype_itemsize.py b/tests/test_dtype_itemsize.py
new file mode 100644
index 000000000..addf03e3f
--- /dev/null
+++ b/tests/test_dtype_itemsize.py
@@ -0,0 +1,101 @@
+# Copyright (c) 2026 PaddlePaddle Authors. 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
+#
+#     http://www.apache.org/licenses/LICENSE-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.
+
+import textwrap
+
+from apibase import APIBase
+
+obj = APIBase("torch.dtype.itemsize")
+
+
+def test_case_1():
+    """Float dtype attribute access."""
+    pytorch_code = textwrap.dedent(
+        """
+        import torch
+        result = torch.float32.itemsize
+        """
+    )
+    expect = textwrap.dedent(
+        """
+        import paddle
+
+        result = paddle.float32.itemsize
+        """
+    )
+    obj.run(pytorch_code, expect_paddle_code=expect)
+
+
+def test_case_2():
+    """Integer dtype attribute access."""
+    pytorch_code = textwrap.dedent(
+        """
+        import torch
+        result = torch.int64.itemsize
+        """
+    )
+    expect = textwrap.dedent(
+        """
+        import paddle
+
+        result = paddle.int64.itemsize
+        """
+    )
+    obj.run(pytorch_code, expect_paddle_code=expect)
+
+
+def test_case_3():
+    """Complex / bool / bfloat16 / float8 — full coverage of less-common dtypes."""
+    pytorch_code = textwrap.dedent(
+        """
+        import torch
+        a = torch.complex128.itemsize
+        b = torch.bool.itemsize
+        c = torch.bfloat16.itemsize
+        d = torch.float8_e4m3fn.itemsize
+        """
+    )
+    expect = textwrap.dedent(
+        """
+        import paddle
+
+        a = paddle.complex128.itemsize
+        b = paddle.bool.itemsize
+        c = paddle.bfloat16.itemsize
+        d = paddle.float8_e4m3fn.itemsize
+        """
+    )
+    obj.run(pytorch_code, expect_paddle_code=expect)
+
+
+def test_case_4():
+    """Aliases: long, double, cfloat, etc."""
+    pytorch_code = textwrap.dedent(
+        """
+        import torch
+        a = torch.long.itemsize
+        b = torch.double.itemsize
+        c = torch.cfloat.itemsize
+        """
+    )
+    expect = textwrap.dedent(
+        """
+        import paddle
+
+        a = paddle.long.itemsize
+        b = paddle.double.itemsize
+        c = paddle.cfloat.itemsize
+        """
+    )
+    obj.run(pytorch_code, expect_paddle_code=expect)