Abstract: In the C/S mode,according to the characteristics of data organization of tile map,the method is proposed by adopting ArcEngine customized layer to draw and project the Tile Map dynamically.The thread pool,asynchronous access technology,cache,and.Net memory management mechanisms are combined to improve the efficiency of the implementation process and user interoperability.In addition,taking into consideration that the tile mosaic technology on Win32 library is specially suitable for processing small amount of data,whereas the tile mosaic technology on open source GDAL library is fit for large amount of data,the two methods are combined to implement efficiently tile mosaic.Finally,the urban planning information inquiry system shows the feasibility of the proposed method.