Abstract: Amethod for determining methylmercury in human hair is described. The sample is digested by hydrochloric acid and extracted with benzene, The concentrated extract is then injected into the gas chromatograph, where methylmercury is directly reduced to the elemental mercury in the hydrogen atmosphere and the mercury vapor is finally measured by Mercury-Analyzer.This method is simple and rapid with a detection limit of 1×10^-11 g Hg and a relative standard deviation of 2.3%. The method is satisfactory for the analysis of human hair samples.