Abstract: To verify the protective result of partial CP to the bottom plate of oil tank, a CP test has been carried out in Yizheng pump station. Two deep well anode groundbeds are installed at the two sides of No.6 oil tank. The measurement on the ground resistance of the well, stray current interference, step voltage of the well and natural potential has been conducted. The results have shown that all the data obtained are in accordance with related standards.