Actually,government investment system is the key issue in current investment system reformation.

Attracting non-government investors such as domestic and foreign finance consortiums,corporations,enterprises,and individuals to invest in infrastructure projects in our country is an efficient way to solve the deficiency of finance investment.

Government guarantees that promises concession rights,investment return,and environment conditions in infrastructure projects is a kind of government behavior,the purpose is to attract non-government investors such as consortiums,corporations,and individual to invest in infrastructures construction.

In order to attract non-government investors such as consortiums, corporations, and individuals to invest in infrastructures construction, the government provides vouches against non-market risks that investors cannot control through market mechanisms.

This paper analyzes the current predicament of environmental protection and raises the countermeasures in terms of public marketoriented service,governmental investment and legislation.

This paper introduces the concepts and functions of the governmental investment, analyzes on the investment scope of the government by using the public selection theory and public property theory, and defines primarily the investment scope of Chinese government by taking the investment of American government as the example.