nstalling of street lights on the lighting poles of an electrical distribution grid is the most common way for supplying of road light. The initial cost of the common lighting projects contains the Installing cost of transformer supplied with the MV line, distribution grid and street lights .The utilization costs include energy consumption and energy losses of electrical lines and transformer. In the other hand applying of solar street lights (SSL) can supply the rural roads lighting in the lack of low voltage distribution lines without the energy consumption and electrical losses and more environmentally friendly. In order to evaluate the using of solar street lights, we have considered case study of Heyran road in the north of Iran. The result suggested that applying of solar street lights are more economical and gives a cost saving of 94 million Rials after 5 years of project implementation.