Abstract: A method is described for the analysis of acetone in cigarette smoke by capillary GC equipped with NPD. The smoke was passed through traps containing 2, 4-dinitrophenyl-hydrazine (DNPH) in HCl solution, in which the acetone were derived to 2, 4-dinitrophenyl-hydrozone. After extracted with chloroform and concentrated under nitrogen, the derivatives were separated and analyzed by capillary GC equipped with NPD. The repeatability and recovery of acetone determined by this method were evaluated. The deliveries of acetone in smoke from 9 com mercial brands were quantitatively determined by internal standard method. The filtration efficiency of cigarette filter on acetone in cigarette smoke was also determined.