Abstract: Aiming at several serious problems in operation process of RenJing Oil Pipeline, such as high operation COSt, non—pigging since the pipeline putting into production, and complicated and changeable oil products transported, the article systemically summarizes the achievements obtained from RenJing Oil Pipeline in recent years.The rheological characteristics of Daqing and J idong blended oil are deeply investigated and a forecast technique for wax deposition law in forward transportation and reverse pumping operation pipeline is recommended.Through RenJing Oil Pipeline alteration, the wax deposition in different level along pipeline radial position under long period non—pigging condition are obtained and basic physical characteristics analysis is conducted.By measuring the wax deposition thickness of RenJ ing Oil Pipeline, the reliability of the forecast technique for wax deposition law in forward transportation and reverse pumping operation pipeline is proved.It is considered that the technique is of guiding significance to ensuring RenJing Oil Pipeline in safety operation.