Abstract: Above ground biomass of 33 Chinese fir trees in a hilly region of Southern Jiangsu aged 2-18 years have been investigated by "divided-storeys" method. After being compared with other methods of estimation, the regression equations showing the relationship between Chinese fir breast height diameter and stem weight(W,), branch weight(W2), needle weight(W3) have been established as follows:W, =0.4073- 0.2322D+0.1360D2Ln W2 =0.1897D- 1.1-753Ln W3 =1.4789-3.3642D-1The total above ground biomass of 3-5 years old trees is ranged 11-39 tons par hectare, 10 years old is 59 tons, 17 years old 78 tons. The proportion of stem weight increases with the increase of their ages as a contrast to the branch and needle. The annual growth varies with the age. The fastest growth appears in the 3rd-4th year, which was 17.3 tons per hectare. The ]2th to 13th year 3.64 tons, and the 14th - 17th year 1.21-1.23 tons. According to the data mentioned above, it is advisable to culture small logs with 14-15 years of age in the Chinese fir forests in this region.