Aim To explore the effect of lipid disorders on the expression and activation of complement. Methods 41 patients with dyslipidemia were distributed into hyperlipemic group(HLP) and hyperlipemia combined with vascular diseases group(HLPC) according to clinical complications.HLP included 17 subjects with dyslipidemia,HLPC included 24 subjects suffered from dyslipidemia combined with cardiovascular diseases,cerebral vascular or peripheral vascular diseases,17 healthy subjects with similar age and gender served as controls.The serum complement components C3,C4,properdin,the plasma complement terminal complex(sC5b-9)and inflammatory markers tumor necrosis factor α(TNF-α),interleukin 6(IL-6) were examined. Results The concentration of C3 was higher in HLP(1.57±0.41 g/L)and HLPC(1.60±0.40 g/L)than in the control group(1.30±0.27 g/L)(both p<0.05);the properdin level was increased in HLP compared with control group(0.46±0.08 g/L vs 0.38±0.07 g/L)(p<0.01).The concentration of sC5b-9 in HLPC(298±110 mg/L)was increased than in HLP(233±101 mg/L)and control group(228±84 mg/L)(both p<0.05).The concentration of TNF-α was also elevated in HLPC than in HLP and controls, there is a significant increase of IL-6 in HLP and HLPC compared with controls.Univariate analysis showed serum C3,C4,Pf were positively correlated with TC,TG,LDLC,HDLC(except Pf with TG),sC5b-9 was positively correlated with SBP,DBP and TNF-α,but no correlation was found between sC5b-9 and lipids. Conclusions The complement components were significantly increased in serum of patients with dyslipidemia,which were positively correlated with lipidemic indexes. No correlation was found between sC5b-9 and lipids,but sC5b-9 was increased in patients with cardiovascular diseases.