Abstract: The biomass and its allocation of a five years secondary forest which regenerated after slash and burn in Xishangbanna were estimated based on standard tree regression analysis (for tree )and clear cut method (for shrub、liana、herb and litter)The result shows that the total biomass was 40.6959 t·ha^-1 of which 30.37 t·ha^-1 are contributed by tree layer The biomass of shrub is 3.77 t·ha^-1 ,and of the liana and herb are 0.55 t·ha^-1 and 0.32 t·ha^-1 ,respectively The biomass of litterfall is 4.48 t·ha^-1 ,dead standing tree is 0.21 t·ha^-1 The optimum regression models of different dominant plants and organs of the sample trees of tree layer in the stands were built.

Key words: ginger, water-water circulation, light energy dissipation.