Abstract:This paper deals with the primary productivity of subtropical secondary shrub thickets and shrub-grasslands in Yixian County of Anhui Province. By using direct harvesting method, the aboveground productivities of six samples of shrub thickets, two samples of shrub-grasslands and one sample of evergreen broad-leaved young forest in the county were measured.The study results show. the productivities of the evergreen broadleaved young forest, the secondary shrub thickets and the shrub-grasslands were 11.94, 6.84 and 3.80 t/ha·a-1 respectively. By comparing with other community types, the productivity of the secondary shrub thickets and shrub-grasslands are lower, and they are less efficient in using the abun- dant natural resources of heat and water in the subtropical zone. The following regression equation was derived from the correlation of the biomass and net productivity of the nine samples: Y=4.27+0.15x, and it shows thar net productivity increases with biomass.