Aim To study the effect of apolipoprotein CⅡ promoter T→A mutation at position -190 on the transcription of the apolipoprotein CⅡ gene and its relationship to the decrease of apolipoprotein CⅡ concentration in plasma. Methods Firstly, the expression vector pGL3 with -190 T→A mutant promoter was constructed using site-directed mutagenesis; Secondly, the expression vector pGL3 with mutant promoter and normal promoter respectively was co-transfected with pRL-TK as an internal control into HepG2 cells by liposome-mediated methods, and expressed transiently. Thirdly, Both firefly luciferase activity drived by normal/mutant apolipoprotein CⅡ promoter from pGL3 and renilla luciferase activity drived by TK promoter from pRL-TK were measured by dual luciferase reporter assay system. Results The results showed that the T→A mutation at position -190 in apolipoprotein CⅡ promoter caused a decrease of 18.96% in luciferase activity compared with the normal apolipoprotein CⅡ promoter. Conclusions The T→A mutation of -190 base in apolipoprotein CⅡ promoter region could debase transcription activity of apolipoprotein CⅡ promoter.