Abstract: Reproductive allocation of biomass in Pinus massoniana was studied in a subtropical evergreen broad-leaved forest at Mt. Jinyun. Values of reproductive allocation increased gradually from the flower bud phase to the flower and fruit phase and the patterns of reproductive allocation of biomass differed between forest successional stages. In a pure forest stand, reproductive allocation was 1.31%, 7.61% and 23.25% at three reproductive stages respectively. In the theropencedrymion, 0.6%, 3.29% and 15.14% respectively. In the forest edge wilderness, 0.76%, 3.78% and 18.44% respectively. The dynamic law of reproductive allocation is "low→high by degree→high→low' during a year. The reproductive age of Pinus massoniana can be divided into four stages in terms of the relationship between the reproductive allocation of biomass and the age of the reproductive individuals. These are the junior, non-stable, stable and declining phases. The reproductive allocation of biomass is significantly related to population density and the light intensity of the community.