Abstract: Reproductive unit size and reproductive modules dynamics of Castanopsis fargesii in Tiantong National Forest Park (TNFP)(29°48'N, 121°47'E)was studied in this paper.The results showed at the number of reproductive C.fargesii individuals and their size were closely related to habitat.The data suggested that DBH of reproductive individuals ranged from 17 to 50 cm, with average of 31. 2& #177;8.0 cm, during the two year's census in TNFP.According to models these individual's age scaled 23.8 to 51. 1 years, with average of 36.3& #177;6.6 years.The DBH of reproductive individuals in the forest edge are smaller than that in forest. The results also suggested that not all individuals necessarily produced fruit in the successive years and the number of reproductive individuals differed markedly during the successive two years.The number of reproductive individuals in 2000 was 2.26 times as much as that in 1999.Additionally, not all reproductive branch within these individuals continuously produced fruit in two successive years, nearly 48.2% of reproductive branches produced fruit in every year.The number of the successive reproductive branch, the number of developmental fruit per successive reproductive branch and fruit-set ratio varied obviously between two years.

Key words: reproduvtive unit size, reproductive modules, Castanopsis fargesii, TNFP