Involving The Positive Provisions Of The Shared Values ​​of Meromorphic Functions

In this paper we study normal families of meromorphic functions, which is an important subject in complex analysis. Much work was made on this respect. In the preface, we give a review about the historical background of complex analysis and research achievements in these fields. The present paper is divided into three parts.In chapter one we state a few usual notations, definitions and basic results in value distribution theory and the theory of normal families of meromorphic function.In chapter two, we discuss the normal families of meromorphic functions concerning differential polynomial and mainly prove Theorem 2.1.In chapter three, we discuss the normal families of meromorphic functions concerning shared values and mainly prove Theorem 3.1, Theorem 3.2 and Theorem 3.3.