Abstract: With the dramatic development of computer network technique, different kinds of information have been enhancing quickly and the requirements for precisely located information gives a strong impetus to the NLP research. Natural Language Processing (NLP) research on the subject that how to make computer understand and generate unrestricted natural language text,such as Chinese, English,etc. It brings computer the understanding ability of natural language meaning and responding the questions persons asked in natural language. Its purpose is building a friendly relationship between human and machine; enabling computers communicate information in a high rate. As an important method for discourse connecting and consistency, the employ of anaphor makes discourse looks brief and anaphora reflects the semantic relations between sentences and makes a discourse be a discourse.