Aim To screen the mutations in lipoprotein lipase(LPL) gene exon 9 and to investigate the effect of mutation on triglyceride(TG) and high density lipoprotein cholesterol(HDLC) level. Methods The exon 9 of LPL gene was amplified by PCR and the mutations were examined by polymerase chain reaction-single strand conformation polymorphism(PCR-SSCP);the natures of mutations were identified by DNA sequencing and polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP). Results Only nonsense mutation Ser~(447)→stop was screened by PCR-SSCP,one subject was homozygous and 77 subjects were heterozygous.The frequency of stop~(447) allele is 9.4% and the incidence of Ser~(447)→stop was(18.6%) in the 420 subjects with normal TG level.The triglyceride level in LPL stop~(447) carriers(1.05±0.32 mmol/L)was lower than that in LPL stop~(447)non-carriers(1.13±0.28 mmol/L)(p<0.05);HDLC level in the former(1.28±0.28 mmol/L)was higher than the latter(1.25±0.27 mmol/L)(p> 0.05). Conclusions Only Ser~(447)→stop mutation exists in LPL exon 9 of 420 subjects with normal TG and the Ser~(447)→stop mutation have the minor effect on lowering TG level.