A novel method for the determination of trace amounts of mercury in sediments by sequential injection cold vapor atomic fluorescence spectrometry coupled with microwave assisted digestion was developed in this paper. Satisfactory results were found when the digestion was carried out at 140 ℃ for 5 min by using 10%HCl-50%HNO3-40%H2O or 30%HCl-20%HNO3-50%H2O media. The linear range was 0.02～30 ng·mL-1 with detection limit of 0.5 ng·g-1. Relative standard deviation for the complete procedure of the analysis of 10 digested sediment samples was 3.7%. Recoveries of the spiked samples were between (91.2±4.3)% and (96.5±4.6)%. The analytical results for three certified reference materials GSD-2, GSD-9 and GSD-10 were consistent with the certified values. The method has been successfully applied to six natural sediment samples. The results indicated that the method was rapid, highly sensitive and precision, and suitable for the determination of trace amounts of mercury in sediment samples.