Abstract: Conditions monitoring and evaluation for the corrosion control system of buried pipeline are very important to safe operating and service life of pipelines. With self-developed conditions monitors of coating system, the evaluation parameters like corrosion current density, pipe-to-soil potential and coating conditions and the effectiveness of CP system are deeply discussed. Then, a mathematical model contained these parameters has been established. An evaluation software has been developed based on this model, which is very helpful to pipeline operator to make maintenance decision.