Abstract: Based on comprehensive investigation of bio-resources in Gucheng Lake in 1999,it is reckoned that the capacity of the lake of sustaining fishes,shrimps and crabs might reach 650-750 t,of which 25 t could be crabs.Aimed at the problem that the output of crabs was not high in recent years, analysis of its causes was performed and consequently solutions were recommended.In order to ensure that multi-functions of Gucheng Lake, besides as a drinking water source,be brought into full play,the regionalization of major ecological functions,the models for calculation of pollution loads and fishery ecological strategies of the lake are worked out.