Zooplankton is one of the most important components in lake ecosystems. The zooplankton abundance and P0₄-P released by zooplankton community in Meiliang Bay and Lake Wuli, Lake Taihu were studied from March to May in 2004. The results showed that the cladoceran density in Meiliang Bay was always higher than that in Lake Wuli. However, the abundance of rotifers was higher in Lake Wuli than Meiliang Bay; and the difference of copepods was not significant. P0₄-P releasing rates ranged from 0.20 to 0.43mgP/(g(DW)·h) in Meiliang Bay, and from 0.19 to 0.54 mg/(g(DW)·h) in Lake Wuli. Present study suggests that nutrient release by zooplankton can play an important role in nutrient regeneration in lake ecosystems.