Abstract: This paper studies dynamic specific property of rough sets.For describing dynamic change degree of rough sets more exactly,this paper introduces the concept of the degree of structure divergence,the degree of nestling up and the degree of complexity.It gives out the property of the degree of structure divergence and the degree of nestling up.It reflects the dynamic change degree of rough sets using the concept of the degree of complexity.Finally,it gives out applied background and an example.

Key words: rough sets, degree of structure divergence, degree of nestling up, degree of complexity