Abstract: Nong-an pipeline is apart of water supply engineering project among the middle cities in Jilin province. The Nong-an pipeline is about 105.358 km long‚, among which prestressed concrete cylinder pipe is about 36km. Because the prestressed steel bar and pipe in soil is subjected to electrochemical corrosion‚, the protection should be taken to prevent them from corrosion. It is proved that the corrosion of steel bar and pipe can be solved effectively by application of cathodic protect systems and the pipelin esystems is safe and reliablel‚ while the service life of the pipeline is improved a lot and important social and economic benefit is expected