It’s well Known that concrete cover provides physical protection of the reinforcement against corrosion , which is very significant in Construction . several corrosion conditions were observed in structures at Tripoli area . Tripoli tap water are using in make concrete mixture . Tripoli tap water , sea water and local aggregate and Reinforced concrete specimens were prepared with different water to cement ratios as well as with different concrete covers . Specimens ( cubes and beams ) have exposed to outdoor (Av. Relative humidity 50% ) and climatic chamber (Av. Relative humidity 85% ) environment . Electrochemical behavior of the specimens was monitoring for two years for both environments . Results have showed that. Water- cement ratio and concrete cover have a significant effect on corrosion rate for specimens mixed with Tripoli tap water and sea water for both exposure conditions .