1. We sought to determine the effects of Q192R polymorphism of paraoxonase 1 (PON1) gene on plasma high-density lipoprotein-cholesterol (HDL-C) levels and the response to statin therapy in Chinese patients with coronary heart disease (CHD). 2. Two hundred and thirty-six patients with CHD were treated with simvastatin 20 mg/day. Fasting serum lipids were determined before and after 12 weeks of treatment. 3. No significant differences were detected among the PON1 Q192R polymorphism with respect to plasma lipids. In addition, the effects of simvastatin to increase HDL-C levels were significantly greater in patients with the RR genotype compared with patients with the QR or RR genotypes (P < 0.05). 4. We conclude that the Q192R polymorphism of PON1 significantly modulates the HDL-C response to simvastatin in Chinese patients with CHD.