Abstract: The software system of pipe irrigation planning based on ComGIS, CAD and database was developed, which realize pipes layout (automatic layout and manual operation) and its optimization, the calculation of water flow, pipe diameter optimization, investment budgetary estimate and economic beneficial analysis. The software system provides many kinds of result output such as graph, text, table and so on. The software can greatly reduce the manual labor and improve the efficiency of the project design. This system has been applied to low-pressure pipe planning of water saving agriculture demonstration districts in Jiangsu Province and the planning results are accurate and reliable.