Based on the analysis of the water resources-society-economic system,this paper stu-died the evaluation index system of the water resources carrying capacity.Macroscopical indexes and integration indexes are put forward to evaluate the water resources carrying capacity. Macrosc-opical indexes are made up of the population and economy scale which the water resources are capable of supporting.They describe whether the water resources carrying capacity is big or small according to the water supply and demand.Integration indexes are made up of carrying capacity exponent and harmony exponent.The carrying capacity exponent reflects the status of water carrying capacity and the harmony exponent reflects the status of the water resources-society-economy system harmony.Based on the evaluation index systems,the mathematical models and algorithm of the water resources carrying capacity were established.Macroscopical indexes were calculated by the water supply and demand.Integration indexes were calculated by the analytic hierarchy process.As a case study,the water resources carrying capacity in North Huaihe River Region of Anhui Province was studied.Both of the systematic indexes and the models developed in this dissertation were calibrated and testified with the data of current year.It is found that the results of the different level year were satisfactory.