Abstract: In order to improve the concurrent access performance with large-scale vector data in WebGIS,a content grid load balancing algorithm is proposed.The server processing capability,service contents,and request time are taken into account.A proposed method to divide large-scale vector data into a content grid,the algorithm of content automatic identification,analysis,aggregation and feedback in the server cluster concurrent environment is discussed.This algorithm implements all servers in the cluster to complete visualization tasks submitted by clients at the same time and realizes task-oriented load balancing.For the extraction and display of large-scale and high-intensity vector data,the algorithm balances the servers’ load efficiently and responds to requests in minimal time.As compared to t traditional load balancing algorithms,the algorithm proposed in this paper has the best performance.The larger the scale,the more obvious is the load balancing effect.