基于mass assignment 理论,提出了两类层次模糊mass assignment系统,并运用构造性证明过程证明了其全局逼近性质.由于类型1层次模糊系统的规则数与输入变量数呈线性关系,类型2层次模糊系统按逼近精度要求引入子模糊系统,因此,此两类层次模糊mass assignment系统可被用来有效地克服模糊规则爆炸问题,即所谓的规则数与输入变量数呈指数关系问题. Based on the mass assignment theory, two types of hierarchical fuzzy assignment systems are proposed, and their global approximation properties are proved by using the constructive proof procedure. Since the number of rules and the number of input variables in a type 1 hierarchical fuzzy system are linear, the type 2 hierarchical fuzzy system Therefore, the two types of hierarchical fuzzy mass assignment systems can be used to effectively overcome the problem of explosion of fuzzy rules, that is, the so-called rule number is exponential with the number of input variables.