The infrastructure scale in Beijing is huge and infrastructure investment is growing rapidly. At present，the proportion of social capital involving in infrastructure construction and operation is still low，but the social capital investment proportion will increase in the future. Social capital involving in municipal infrastructure presences many problems such as imperfect service mechanism and policy environment，market barriers，narrow financing channels，hard to guarantee operations rights，unsound market exit mechanism，low quality，etc. The key to solve these problems is to develop land preferential policy，protect the legitimate rights and interests of social capital investors，introduction of financial support policy，encourage financial innovation，improve project construction supporting policy，strengthen social capital exit mechanism and exit policy，strengthen supervision and management of the social capital and provide service guarantee.