Objective To investigate the association between c.553G>T polymorphism in apo A5 gene and the level of serum lipid in the Han population of Jiangsu Province,China.Methods Using polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP)we analyzed the genotypes and calculated the frequency of alleles in 199 hypertriglyceridemia(HTG)patients and 225 healthy individuals.The levels of serum lipid profiles were also studied by biochemical methods.Results The frequency of T alleles of c.553G>T polymorphism in HTG patients was significantly higher than that of the control group(12.56% vs 4.67%,P<0.001).Compared with the wild type GG,TT homozygotes and TG heterozygotes also showed a correlation with increased serum concentration of TG (P<0.001) and decreased concentration of HDL-C (P=0.011).Conclusions The apoA5 c.553G>T polymorphism is associated with the elevation of serum triglyceride,and is also strongly related to hypertriglyceridemia.