How to describe the dynamic process of belief functions in the Dempster—Sharer theory is a very important research field．The specialization of evidence functions is a kind of important method to express the dynamic process．In this paper，the authors dis-CUSS two different definitions for the specialization，correct Kruse'S mistakes in his book“Uncertainty and Vagueness in Knowledge Based Systems”and prove theorems 6.10 and 6.11 in the book by using adverse orders．At last，based specialization，the authors discuss some relationships among three kinds of condition rules which lead to dynamic pro-CeSS of belief functions．