This paper presents a method of modeling a fuzzy system with fuzzy and nonlinear border,obtaining systematic structure by clustering analysis,applying BP network (BPN) to generate rule bases antecedent function and using RBF network (RBFN) to approximate each rules conclusion function not only because of efficient capability of approximation nonlinear function of BPN and RBFN but also because of quickness of training speed of RBFN. In addition,structure design and training of relevant networks are discussed in detail. Finally,the structure optimization and overstudy of RBFN are discussed.