Taking Chinese fir (Cunninghamia lanceolata (Lamb. Hook.)) forest as the subjects of this study, 95 sample plots were selected from 12 counties in CFI system (2009) of Zhejiang province. According to the average trees of 95 plots, 95 analytic trees were selected outside the sample plots but similar with them, and simultaneous equations of DBH-H equation and biomass model were established. Then, we compared the estimation outputs of 20 biomass models, calculated the ratio of stand biomass and stand volume which is exactly BEF, established the relationship between stand stock and BEF. According to Zhejiang CFI system 2009 (eighth), we calculated Chinese fir forest BEF in Zhejiang province is 0.7453 t/m3, and Chinese fir forest total biomass is 37.2154 million tons, uncertainty for 5.739%. Finally, based on IPCC(1996) carbon density default value (0.50), 1 m3 growth of Chinese fir forest absorbs CO2 1.3663 t.
