Abstract: In the eastern oil fields, crude oil output is getting lower and lower, which has caused low or ultralow flowrate pipeline operation, thus bringing transportation difficulty due to the unsatisfied thermal working condition. Measures of heat treatment and pour point depression had been tried to modify crude oil for the purpose of depressing pour point and reducing viscosity so that the oil flow property got improved. Nevertheless, transportation problems still remain due to modification limitations such as the limited degree and the problem of real effect of crude oil modification. As a permanent solution to the problem of lower temperature flow, a new method of. transplanting the technique of molecular sieves and non-hydra dewaxing for pour point depression is put forward in the paper with three different kinds of crude oil choser, for the experiment of pour point depression and viscosity reduction by means of molecular sieves. If this technique is used in oil pipeline, an extra provision for pour point depression and viscosity reduction shall necessarily be allocated at the initial station.