Abstract: On the basis of architecture of rough set theory and evidence, this paper analyzes different methods of mass functions in rough set theory and evidence synthesis, and researches the relationship between the subdivision in partial sequence stratigraphic and evidence synthesis. According to the sub-division in partial sequence stratigraphic changes, this paper demonstrated that mass function which is got in the subdivision of supremum, infimum and all upper and lower bounds in the sub-partial order on the lattice, does not correspond to the mass function of evidence synthesis in evidence theory. Therefore,it clarifies the relationship between the mass function acctuired from the subdivision in dif- ferent knowledge granularity levels and mass function got from evidence theory.

Key words: Division, Partial sequence stratigraphic subdivision, Granularity, Mass function