After six - time whole lake investigations in C. fluminea resources and relative studies on ecology and biology between October 1997 and September 1998, reserves of 47, 000 ton C. fluminea in Tia lake has been ascertained, which, can supply over 5, 800 ton"Tai Lake living C. fluminea "per year. The resources are distributed unevenly, with the most density in the west shallows. The low density zone of below 10/m2 covers 70 % of the lake area. Food is the key factor to influencing the distrbution of C. fluminea. There is a opsitive relation between the amount of sulphide of the bottom earth and the density of black shell C. fluminea. As to species population structure, the small size is dominent, and the commodity C. fluminea rate of over 1. 8 cm in length is 14%only. Tai Lake C. fluminea start to breed in the first ten days of April, with a reproductive peak in June,July, August, and wane to stop in October. The bread condition of Tai Lake C. fluminea is various and the reproductive capacity is week in the whole. The resources fluctuate greatly within a year. Reproduction and the pump-drawing of engine boat are the primary factors. Presently the growth and decline of the resources are in balance. Tat Lake C. fluminea resource evolution has gone through three stages: increase steadly in the 1970 ’s, rise firstly and fall later in the 1980’s, decline graduately in 1990’s.