Corrosion protection is very necessary for all steel or other types of metal, especially in buried pipes (underground construction). Direct contact between pipe materials (Carbon steel) can accelerate the corrosion rate. This is the case with the 20 inch pipe project working on the pipe installation. Initially to prevent this type of corrosion was done cathodic protection, but the result of examination was proven that there was a leakage of the potential distribution protection to the ground. Therefore it is necessary to do a distribution protection simulation to get how many anodes (magnesium package) to meet protection needs. The anode distance simulation results on the distribution of potential are carried out with the following variations: distance of every 45 meters, distance of every 30 meters, distance of every 20 meters, and distance of anodes every 15 meters. Based on the simulation results it is found that the anode distance cannot meet the minimum protection (-850milli volt) except at a distance of 15 meters. Installation of anodes at a distance of 15 meters with each pair of distance of 4.9 meters proved that the simulation results have met the minimum potential for corrosion protection. So that it can be used as a reference for installation of anode spacing for pipe corrosion protection.