With the advantage of neural netw ork in nonlinear problem, aradial basis function is used to improve conventional BP network. According to the condition of inspecting water quality in Dawen river of Huang river,the ANN model of evaluating water quality is put forward. The training stylebook takes 7 polluted target of this water quality as samples , and the water quality is evaluated using the trained network. The calculating results are analyzed and compared. This method is used to speed up the convergence and impove the performance.