Abstract: An analysis on corrosion and corrosion mechanism of surface gathering line in Cainan Oilfield of Xinjiang is carried out. The analytical results show that the corrosion of gathering line can be divided into two categories, one is normal corrosion, and the other, belongs to abnormal corrosion. Because the pipeline waves with the hilly terrain, the former occurs in the pipeline system all the time, the latter often occurs in the upward direction of pipeline.