Abstract: Core competence is a critical factor for enterprises to win in market competition.It includes many elements,which can be obtained by internal accumulation or external alliance,cooperation,MA,etc.The transformation of Tech-knowledge is affected by both enterprises' internal and external environmental factors,so how to transform Tech-knowledge into enterprises' core competence is the problem in reality for many international enterprises.This paper starts with constructing elements and forming rules of core competence.Then it analyzes problems occurring during the process of obtaining core competence through cross-border MA.