This article discusses the differences between the Chinese preposition "dui" and the Japanese compound case particle "nitaishite" on the use as the object marker. The result of the research reveals that the differences are to be found in the following manners:

1.The scope of predicate of "dui" is wider than that of "nitaishite".

2. When the focus is decided by word order, no matter whether the object is at the beginning of the sentence or not, "dui" can be used. When the focus is decided by word order and the object is at the beginning of the sentence, "nitaishite" can be used, but when the focus is decided by word order and the object is in the middle of the sentence, "nitaishite" can not be used.

3. When the focus is decided by accent, we can either use the Chinese preposition "dui" and the Japanese compound case particle "nitaishite" to show the object.