Abstract: In response to the high wax content in the JZ crude oil, a variety of carboxylic acid ester copolymer type pour point depressants (PPDs) were synthesized and the depressant of LF-04 was chosen as the best one. Subsequently, factors affecting its effect on the depression were analyzed. It was found that the optimum heat processing temperature for the JZ crude oil with the additive of LF-04 is above 50℃, and the optimal PPD concentration is 400mg/l. In addition, the pour point of the crude oil was reduced from original 21℃ to 9 ℃ with the presence of 400 mg/L inhibitor, and correspondingly, the abnormal point was reduced from 45℃ to 40℃. Apart from the above, at the temperature of 25℃ and shear rate of 16 s^-1, the apparent viscosity of the crude oil with the addition of LF-04 at the concentration of 400 mg/L was decreased by 70.5%. Consequently, based on the the good static stability, depressant of LF-04 has good prospects of popularization and application in oil fields.