Disjoint variation is one of the variations of set functions, which plays an important role in the decomposition of set functions. In the paper, we generalize the definition of disjoint variation to the fuzzy set functions and the fundamental t-norm Tinfin and Sinfin are considered as the operation of the fuzzy sets. Some theories are proved for finitely Tinfin -additive fuzzy set functions with bounded disjoint variation and some properties of disjoint variation of the non-additive fuzzy set functions are given.