Abstract: In order to investigate the influence of smoking regime on the delivery of hydrogen cyanide(HCN) in mainstream cigarette smoke,4 cigarette samples were tested under different smoking regimes on smoking machine.The results showed that the delivery of HCN varied greatly with the change of smoking regimes.Increasing puffing volume,decreasing puffing duration,shortening puffing interval,reducing filter ventilation and butt length,would increase HCN delivery in mainstream smoke,however,those correlations were not linear.It suggested that HCN intake could be reduced by changing smoking behavior if the number of smoked cigarette unchanged.