Our country is facing serious water problems. As the important factor that affect water resources carrying capacity, the influence of social and economic activities on water resources is obvious. By analyzing the key element of socio economic driver that affects water resources carrying capacity, establishing the principal component regression model , the driving factors which influence the carrying capacity of water resources in Jiangsu were classified into three kinds , the influence degree of the driving factors was gained. Combined with grey neural network theory and six important factors which is coming from the three main factors, the grey neural network model was established to predict the total water uses in Jiangsu Province from 2012 to 2013.The prediction accuracy of the model is higher.At last, the paper gave relative policy recommendations by combining with the actual situation of Jiangsu Province.