Abstract: The Total Toxic Residues (TTR) of aldicarb were extracted from tobacco leaves and soil with acetone and the mixture of acetone and water (1:1, Ⅴ /Ⅴ), res- pectively; then oxidized to aldicarb sulfone by hydrogen peroxide and acetic acid. The extract was cleaned up by liquid-liquid separation and columnar chromato graphy, then determined with a sulfur model-flame photometric detector in gas chromatography. The rate of recovery ranged from 83% to 105%, and the minimum of detection in fresh tobacco leaves, cured tobacco leaves and soil was 0.0169ppm, 0.0339ppm and 0.0135ppm respectively.