Abstract: Objective To establish a method for the determination of tin in urine by wet digestion hydride generation -atomic fluorescence spectrometry. Methods After the samples were digested with the acid mixed with nitric acid and sulfuric acid(40:1,volume ratio), 50μg/L thiourea-50μg/L ascorbic acid were added in it as a masking agent and 10.0 g/L potassium borohydride were added as reducing agent. The determination of tin concentration in urine was done by hydride generation-atomic fluorescence spectrometry with 0.5% (volume ratio)sulfuric acid for load flow. Results Within the linear range of 10.0-100.0μg/L, the obtained regression equation was y (the urinary tin concentration)=22.847 x (peak area) + 26.395. The correlation coefficient was 0.999 7. The detection limit was 0.33μg/L;RSDs range from 0.96% to 2.64% and the recovery rates 97.27%-101.30%. Conclusion This method is simple, fast, accurate and sensitive, and the matrix interference is little. As the atomic fluorescence apparatus is relatively cheap, this method is suitable for the determination of urine tin concentration.