Abstract: The function of forests for fixing carbon and releasing oxygen gives full scope to relieve the global climate warming,thus forest carbon monitoring is more important,and carbon content factor (CCF)is a key index. Based on the data of larch (Larix spp)in northeastern China,the CCF’s of different organs were analyzed systematically using hypothesis test and regression analysis. The results showed:(i)the CCF’s of different organs are almost significantly different,and the order by CCF from the largest to the smallest is stem bark,branch,foliage,root,and stem wood; (ii)the CCF of upper stem wood is significantly larger than those of middle and lower stem woods,whereas the CCF’s of middle and lower stem woods are not significantly different; (iii)the CCF’s of roots with different sizes are not significantly different,and the CCF’s of root and aboveground biomass are also not significantly different; (iv)the CCF’s of different organs are relatively stable,and are not related significantly with the tree diameter and height,but the CCF of whole tree,especially the CCF of root,is related significantly with the tree origin.

Key words: carbon content factor, biomass, hypothesis test, regression analysis, Larix