On the base of describing the police background of "separating secondary lines of business from core business and turning secondary lines into independent companies" for state-owned large and medium construction enterprise, this paper analyses the importance and necessity of "separating secondary lines of business from core business and turning secondary lines into independent companies" .

With the opening of Chinese construction market,large national construction enterprises are facing with increasingly severe competition.

At the present,large national construction enterprises have been still meeting with urgent external pressure and internal demand of property system reform.

The establishment of effective encouraging mechanism is the prerequisite for both ensuring state-owned large and medium-sized enterprises value maintaining and increasing and for realizing their prop role in the national economy.

As the core power of China s economic, state-owned large and medium-sized enterprises especially equipment manufacturers participate in the international competition.

State-owned large and medium-sized enterprises play a leading role in nation s economy, in order to ensure state-owned large and medium-sized enterprises to maintain sustainable development, we must insist on the policy of technology innovation.