This study focused on the lexicalization phenomenon of the adverbs like ‘X+Wei(爲)’ and the semantic functions of ‘Wei’， using the theory of grammaticalization analysed the relationships among the meanings of Wei, and discussed the conditions and mechanisms during the lexicalization process of ‘X+Wei’. According to the results of this study, the ethmological meaning of Wei-‘work’, was great influence on the meaning development of Wei. Beside that, reanalysis, atemporalize and inference mechanisms were played an important role on the lexicalization of ‘X+Wei’. The suffix ‘Wei’ has two kinds of semantic functions, one is predicational function and the other one is leading the change.