Abstract: Snail population is crucial for controlling schistosomiasis transmission.The climate,geographical environment and the marshland characteristics in the area of Poyang Lake are ideal for snail reproduction,and thus make Poyang Lake one of the major endemic sites of schistosomiasis in China.The snail growth model is designed and realized based on the complex adaptive system(CAS) theory and agent technology such as swarm platform and Java to simulate some important factors in snail life cycle.At last,data collected in the marshland named Changjiang are collected to test the model.The simulation result shows that the model can be used as a tool for estimating the numbers of snails in controlling schistosomiasis.