Abstract: This paper uses non-linearity method to resolve the problem for simultaneous measurement of the concentrations of mixtures of metal ions.Here we wrote a multilayer feedforword net with the backpropagation learning algorithm(BP) and a neural network based on radial basis functions with MATLAB v5.3,and compared the circumstance for them to correct,and discovered it is better than BP network of RBFE network of system inside.The complexometric titration that we use,with ethylene glycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid(EGTA) is not added the buffer liquid,and we discuss the relation of the volume of titration V,the value of pH and the ionic original solution C0M.Finally RBFE network apply to simultaneous measurement of four cent metals leaving the son CuZnPb such as Cu,Zn,Cd and Pb.