Polymer of n-alkyl substituted acrylate(PA)with the alkyl side chains C_(16—30)were synthesized.Their crystallinity,solubility and effect on pour point depression were studied.Results showed that onlycarbon atoms located far away from polar groups of PA pour point depressants participated in crystallization.When the number of carbon atoms that participated in crystallization is about three fourths of the averagecarbon number of wax in crude,the effect of PA is the best.The molecular weight distribution of PA pourpoint depressant has little influence on the effect of pour point depression,and the average molecularweight of PA in the range of(1.5—2.2)×10~4 shows the best effect.The introduction of polar groups into themolecule of PA can improve its performance.However,a too high content of polar groups in PA wouldcause deterioration,and even lead to loss of PA’s performance for pour point depression. Polymer of n-alkyl substituted acrylate (PA) with the alkyl side chains C_ (16-30) were synthesized.Their crystallinity, solubility and effect on pour point depression were studied. Results showed that that onlycarbon atoms located far away from polar groups of PA pour point depressants participated in crystallization. WHEN the number of carbon atoms that participated in crystallization is about three fourths of the averagecarbon number of wax in crude, the effect of PA is the best. molecular weight distribution of PA pourpoint depressant has little influence on the effect of pour point depression, and the average molecular weight of PA in the range of (1.5-2.2) × 10 ~ 4 shows the best effect. introduction of polar groups into PAO improve the performance. However, a too high content of polar groups in PA would not deteriorate, and even lead to loss of PA’s performance for pour point depression.