diff --git a/graphic/graphic_2d/native_drawing/drawing_text_typography.h b/graphic/graphic_2d/native_drawing/drawing_text_typography.h
index 3a5e5ef589f97e2046dffa6367001209a535010c..f18cf1a57cc741ea01f5a9a6ae44d624cb9d2c45 100644
--- a/graphic/graphic_2d/native_drawing/drawing_text_typography.h
+++ b/graphic/graphic_2d/native_drawing/drawing_text_typography.h
@@ -595,11 +595,14 @@ double OH_Drawing_TypographyGetMaxWidth(OH_Drawing_Typography*);
 double OH_Drawing_TypographyGetHeight(OH_Drawing_Typography*);
 
 /**
- * @brief Gets the longest line.
+ * @brief Obtains the width of the longest line. You are advised to round up the return value in actual use.
+ * When the text content is empty, the minimum float value,
+ * that is, -340282346638528859811704183484516925440.000000, is returned.
  *
  * @syscap SystemCapability.Graphic.Graphic2D.NativeDrawing
- * @param OH_Drawing_Typography Indicates the pointer to an <b>OH_Drawing_Typography</b> object.
- * @return Returns the length of the longest line.
+ * @param OH_Drawing_Typography Pointer to an <b>OH_Drawing_Typography</b> object, which is obtained by
+ * {@link OH_Drawing_CreateTypography}.
+ * @return Returns the width of the longest line.
  * @since 9
  * @version 1.1
  */