Based on the statistical characteristics of Chinese maximal noun phrases (MNPs) in a Chinese corpus with 5 573 sentences,two efficient identifying algorithms for Chinese MNPs:(1) To identify MNPs by using boundary distribution probabilities; (2) To identify MNPs by using internal structure rules,are proposed in this paper.Experimental results show better performances:precision 85.4% and recall 82.3%,by using identifying algorithm (2).