Abstract: An anodic-stripping voltammetry method is modified for trace tin determination.Hydrochloric acid-methyl alcohol systsm was used as a supporting electrolyte in which Sn gives a well-defined stripping peak. Pb doesn't interfere with the determination of Sn and can be simultanenusly determined under the experimental condition deseribed without separation. The precision, sensitivity, recovery and interference of various coexisted ions were discussed. 10^-6%Sn in wine and 10^-5%Sn in asparagus were determined by this method with average errors of recovery less than 10%.