In this study the prediction of the erosion profiles during ECM of the spiral hole was presented. By assumptions, the major points were simplified into one-dimensional problems. The theoretical and computational model was built to illustrate the profile movement as the time elapses. The analysis was based on the law of electrolysis and the software MATLAB was used. Verifications were done through experiments and the deviation was 7.5% between theoretical and experimental result. On the basis of the prediction of the erosion profile, the applied parameters could be estimated.