To investigate the allocation of water environment capacity in Northern Canal, based on hydrodynamic and water quality models and the collected annual averaged discharge and related pollutant data, two main pollutant factors, that is, COD and NH3—N, are chosen to calculate the response matrix between the tributaries of the North Canal and point sources and control sections . Then, linear programming(LP) model is used to optimize the allocation of water environment capacity at each point sources or tributaries. The results indicate that the allocated amounts of capacity at all point sources or tributaries are negative, which need to be cut down by adopting appropriate measures. The average reduction rate of COD is about 30%~50%, while this value is in the range of 40%~70% for NH3—N. Besides, linear programming method is proven to be suitable for the allocation of water environment capacity of rivers and can be one of useful tools for this problem.