Abstract: The forest carbon storage maturity of Cunninghamia lanceolata plantations grown under different site conditions in southern part of Henan Province was studied by means of the carbon measurement methods commonly applied to the international projects of forest carbon sequestration, and the influences of different site conditions on the carbon storage maturity were also analyzed. The results showed that the better the site conditions were, the lower the maturity age of carbon storage would be and the more the average carbon storage in maturity age would be. The determination of carbon storage maturity would be of great significance for tree species selection and for the determination of project duration of forest carbon sequestration.