As an important part of forest sink, the forest conservation carbon sequestration project has been incorporated into many action initiatives to address climate change and the carbon markets with its multi-benefits.Based on the market demand of China's voluntary emission reduction of greenhouse gas, this paper studied the methodology of forest conservation carbon sequestration project that fits the conditions in China in terms of carbon pools selection, baseline scenario determination, additionality argument and carbon stock measurement, and proposed the new methodology of forest conservation carbon sink project that uses biomass accumulation method, biomass expansion factor method and attenuation function method and takes woody products, aboveground biomass, litters and dead trees as the carbon sink, with a view to providing theoretic basis for developing China's forest conservation carbon sink project and establishing the national carbon trading market.