Abstract: According to 89 trials on N,P, K in paddy field, it was suggested that the typicality of three-fertilizer efficiency model was desided by the existence and the character of extreme value.Based on the distinguished results of extreme value,three-fertilizer efficiency model may be clas-sified as typical model and three types of non-typical model,The character of different types of three-fertilizer efficiency model and the distinguish methods were analysed, and the recommenda-tory fertilization for non-typical model was contributed in this thesis.