Abstract: In order to determine the hydrogen cyanide content in mainstream cigarette smoke, a headspace-gas chromatography method was developed by using sodium hypochlorite as derivative reagent. Ten cigarette samples of different tar deliveries were determined, the results were compared with those of continuous flow method and ion chromatography method. The results showed that:1)The diluted samples of the absorption solution of gas-vapor phase matter and the extract of total particulate phase matter were stable within 12 hours, the variation rate of determination results was less than 5.0%. 2)The detection limit of the developed method was 0.032μg/cig with the precision (RSD)of 3.9% and the recoveries ranged from 102.5% to 107.2%. 3)The determined results of the developed method were 3.31% to 5.87% higher than those of continuous flow method and showed no significant difference comparing with those of ion chromatography method.