Abstract: An analytical method for determination of mancozeb residue in watermelon, watermelon leaf and soil by gas chromatography headspace has been established. The working curve of mancozeb was used for determination and calculation, solving the problems caused by the unstable mass conversion coefficient of carbon disulfide/mancozeb. The method is characterized by high accuracy with 0.1 mg/kg minimum detectable level of mancozeb in samples. It can be satisfactorily applied for determination of mancozeb residue.