Corpus based method has been widely applied in natural language processing and satisfactory result has been obtained in Part of Speech tagging; But there still exist many problems in syntactic analysis based on the method. This paper gives a dynamic programming algorithm for corpus based parsing. This algorithm can construct all kinds of syntactic trees from bottom to top step by step, and choose the best one from them in polynomial time, like enumeration method, by which, optimal one is obtained in exponential time! This paper also disc...