Electrocoagulation is an electrochemical method for treatment of water and wastewater. The present study has been evaluated the performance of electrocoagulation method with anionic polyelectrolit in batch mode for removal of iron and manganese from surface water. Soleymanshah dam of sonqor located in the northeastern part of Kermanshah Province, Iran. The water of this dam contains high level manganese. The design of experiments was based on a central composite design (CCD), and the analyze of data carried out using response surface methodology (RSM). According to the analyze of the process, the effects of significant variables such as voltage (5- 25), reaction time (20-60), temperature (10-30), anionic polyelectrolit (0.1-0.3 mg/L) on the removal efficiency of iron and manganese from surface water were investigated, using aluminium electrodes at natural pH. Iron and manganese concentrations and aluminum residual in the treated water were measured using inductively coupled plasma. The results of the ANOVA analysis showed that the model fitted well with manganese and iron reduction. At the optimum conditions (voltage of 5 volt, reaction time of 20 min, temperature of 10 °C and anionic polyelectrolit 0.3 mg/L). In this condition, manganese and iron removal were 77.5%, 75% respectively and aluminum residual in treated sample was 0.154 mg/L. The results showed that electrocoagulation process with anionic polyelectrolit is an effected method for manganese and iron removal from surface water.