The traditional cathodic protection (CP) criteria of “-850mV(vs CSE)” is no longer effective when pipelines suffer from alternating current(AC) interference. And unfortunately the CP criteria for buried pipelines in the presence of AC interference have not reached a consensus so far. In this work weight loss tests on Q235 steel in the simulating soil solution of 4g/L Na2SO4were conducted to explore the reasonable CP potential for Q235 steel under AC interference. The experiment results showed that the corrosion rates of Q235 steel under different CP potentials were affected significantly by AC current and the effects depended on the applied CP current density. What’s more AC induced corrosion could be controlled by increasing CP level when AC current density was below 300A•m-2. However the corrosion of Q235 pipeline steel would be accelerated when the CP potentials were too negative. Moreover a reasonable CP potential range for Q235 steel in the presence of AC interference was proposed based on the experiment results.