Abstract: The concept for equivalence of networks is discussed in this paper, the heart of the content explores how to set up the conditions, which can be used to judge the networks to be equivalent or not. Seven propsitions are put forward in the paper to thoroughly talk over the problems for weakening the conditions of judgement. At the end of the paper some examples are enumerated. These examples show that the theses advanced in the paper can be used to simplity the analysis of some networks, hence this paper possesses certain significance in the both theory and practice.