A daily discharge prediction system is developed by the Artificial Neural Networks (ANN) using real daily discharge data, ANN have great generalization ability and guarantee global minima for given training data. In the paper, with 8 years long-term daily information, the ANN can construct a very high precision daily discharge forecasting system. The experiment shows that the predicted curve well regresses the observed curve. It can be concluded that this technique can be seen as a very promising option to solve nonlinear regression.