Abstract: Based on the material of stem analysis, Phoebe zhennan natural secondary forest of state forest farm in Yongchuan district of Chongqing city was analyzed. The results showed that,the mean DBH of 60-year Phoebe zhennan was 38.81 cm, mean annual DBH increment was between 0.63 cm and 0.81 cm. The mean height of 60-year Phoebe zhennan was 35.30 m, mean annual height increment was 0.68 m. The maximum of current annual DBH increment and height increment were 1.00 cm and 1.00 m, and they were occurred from 15 years to 20 years, the minimum of current annual DBH increment and height increment were occured in 55~60 years, they were 0.31 cm and 0.14 m, respectively. Until the 60th year, the growth of volume is in a state of continuous growth. The volume of 60-year Phoebe zhennan was reached 1.713 1 m³, mean annual volume increment was 0.017 4 m³. The maximum of current annual volume increment occurred at 45-year-old and it was 0.047 5 m³. The growth dynamic models of height,DBH and volume of Phoebe zhennan were established with the cubic polynomial, the goodness of fit all exceed 99%. Three regression equations were y=-5.275+1.203x-0.007x²-0.000 006x³,y=-5.109+1.087x-0.004x²-0.000 06x³,y=0.182-0.035x+0.002x²-0.000 002x³, where y is DBH, height and volume, x is age. Comparing with fast growing tree species Cunninghamia lanceolata, the height and DBH increment of 38-year Cunninghamia lanceolata were 18.34 m and 25.52 cm, the tree height and DBH growth rate of Phoebe zhennan were higher than that of Cunninghamia lanceolata, in addition to the high velue of Phoebe zhennan wood, it can be widely cultivated and applied as the precious tree species in China.

Key words: Phoebe zhennan, growth regularity, mean annual increment, current annual increment