Galvanic corrosion between law alloy steel and copper couple in 4 % NaCl solution was studied and the effect of some variable were investigated. The effect of area ratio, temperature and rotational speed through the electrolyte have been investigated. An increase in galvanic current was observed when we increased the area ratio of law alloy steel to copper and the galvanic potential moved to extra negative direction. When the temperature of solution increase led to increase the galvanic current and shifting the galvanic potential to extra negative direction. The galvanic current rises clearly with increasing of rotational velocity of agitator with shifting the galvanic potential to extra positive due to mass transfer control the process. In addition, increase the diffusion of oxygen from bulk of electrolyte to the metals surface.