In this paper we discuss the application of semi-supervised machine learning method-co-training on Chinese Text Chunking. Firstly, we give the definition of Chinese chunk,then the formalized definition of co-training algorithm.We proposed a example selection method based on the consistence, using two classifiers: Transductive HMM and fnTBL to combine a classification system to perform the Chinese text chunking task with the small-scale labled Chinese treebank and large-scale unlabled Chinese corpus. The result were compared with the self-training result and the result of the non co-training experiment in which we only used the small-scale Chinese treebank as training data and use one classifier(Transductive HMM or fnTBL) to recognize the Chinese chunk. The improvement is significant, the F value of the two classifiers reached 83.41%,85.34%, get a improvement of 2.13 points and 7.21 points respectively.