Abstract: The rapid change and development of the world economy bring about more challenges to the development and expansion of the state owned enterprises . Onthe basis of the enterprises Magnitude Economical Theory and the enterprises’realistic expanding desire ,and inthe theoretical frame of the lifecycle of the core product , this paper discusses the different correlated merging actions that are to realize the enterprises expansion in the variant market circumstances . The analysis and thinking modes put forward in this paper can probably provide references for the managers of the state owned enterprises intheir decision- making practice .