Abstract: There is multi-correlation among the factors which impact the city water resources capacity The traditional least square method can distort and destabilize the multivariate regression model.The partial least-square regression(PLS) is applied to build the city water resources capacity model based on the main component analysis and typical correlation analysis.Through distilling component,the model is suggested to solve the interactive correlation among the independent variables.The author has analyzed the PLS1 model,the result is satisfactory.