In this paper, I focused on sentences with de-phrase in Mandarin Chinese, which have been discussed in the literature (Huang 1988, Li 1990, Aihara 1991, Sybesma 1999, Cheng 2007). It is well-known that de-phrase denotes manner reading and resultative reading. It is also claimed in previous studies that de-phrases with two different readings are analyzed as a result of the different structures with different lexical items (Li 1990, Cheng 2007). In this paper, I suggest that there is only one lexical item de and the difference between resultative reading and manner reading depends on the boundedness of XP that de selects. Moreover, I also claim that the subject NP in de-phrase plays a crucial role to determine the boundedness of de-phrase.