Parsing requires the quantitative information of grammatical functions of part of speec h.This paper studied grammatical functions of part of speech by using the Chinese Dependency Treebank based on the Probabilistic Valency Pattern Theor y.According to the frequency,we divided grammatical functions of verbs into principal function,secondary function and part functio n.From the aspect of quantitative analysis,we validated and complemented formers’ conclusion,which helped us to have a clearer understanding of grammatical functions of verb s.This paper is also a development of the Probabilistic Valency Pattern Theor y.