The word"zuo wei"in contemporary Chinese may be distributed in ten sentence patterns, in which the "zuo wei"as a verb is distributed in the first six patterns and the prepositional"zuo wei"the last four patterns.The verbal"zuo wei"and the prepositional"zuo wei"performed great oppositions in their semantic meanings and syntactic functions.In the process of evolution the phrases led by"zuo wei"consistently shifted forward in the linear sentences, and at the same time its syntactic functions gradually degraded from predications to adverbial modifiers.Therefore, "zuo wei"finished its progress of grammaticalization, changing from a verb to a preposition.