The environment impact assessment studies have started with the approval environment impact assessment pattern by sustainable development committee in 1997, but theirs reports are prepared with the different qualities and generally are not comprehensive. Therefore, for considering all aspects of environment, complimentary studis are neccessary. Althoagh many of iran’s dams have environment impact assessment report. they created several problems in their areas. In this study for environment impact assessment of Zablo Dam matrix method was used. Study results have shown that the sum of negative effects are 632 and the negative effects are -524. so that Chahnimeh Four Construction despite of having negative impacts has higher positive impacts on social, economic and biological environment Then Chah nimeh could be implemented.