Abstract: In order to understand the relationship between Cd and pH,COD,TN,TP,and find out the spatial distribution and source of Cd,SPSS and GIS models were used to analyze the detection results of pH,COD,TN,TP and Cd in 10 monitoring points of the main stream of Nyang River,and the spatial distribution of heavy metal Cd in the main stream was analyzed by inverse distance weight interpolation.The results showed that:(1) the main stream water body of the Nyang River met the class III surface water quality standard in the flood season,and COD was the most variable index in the spatial distribution,Bahe River and Niangqu River had great influence on the water environmental index concentration in the main stream of Nyang River.(2) There was a significant positive correlation between TN and pH,Cd and TP in the main stream water(P < 0.01).There was a linear multiple regression relationship between Cd and TP.The regression constant was 0.003,and the regression parameter was 83.072.(3) The metal Cd in the main stream water decreased gradually along the river,mainly from natural mineral resources and agricultural non-point source pollution along both banks of the river.The results can provide a reference for water environment protection and control of heavy metal Cd in Nyang River Basin.