A method for determination of trace mercury in hair by hydride generation atomic fluorescence spectrometry under normal or high temperature and high humidity condition was described. The ways of samples pretreatment, analysis and rapid clearing up bad memory were researched. The results showed: that the effect of instability of mercury can be cushioned under high temperature and high humidity condition by choosing much negative high pressure and control long the fluorescence intensity of standard blank. There weren't evident differences in the measure results of standard graph, standard and sample between normal and high temperature and high humidity conditions. When the reducer concentration was more than 2.5 percent or less than 1.5 percent the fluorescence signal was often overrun or disappeared. The sensitivity and stability of instrument weren't easily balanced. Due to sulfuric acid remainder, the fluorescence intensity of sample blank was higher than that of standard blank, especially under high temperature and high humidity, so in the proceed of sample pretreatment sulfuric acid was used scarcely. The bad memory effect can be cleared up rapidly by correction of negative high pressure and correction of of timized standard graph. The method was rapid and accurate. The relative standard deviation (RSD) was equal to or small than 1.1%. The detection limit of the method was 0.006 ng x mL(-1).