Abstract: Behavior of chitosan as a reagent for enrichment of inorganic tin and the condition of elution were studied.Tin in the eluate was determined by the AFS with hydride generation.Both the stannous and stannic tin was adsorbed on chitosan at pH 4.0 with adsorption efficiency of 96% and 99% respectively.Tin(Ⅱ,Ⅳ) was then desorbed quantitatively from chitosan by elution with 5 mL of H2SO4 (4+96).The eluate was diluted with 5 mL of H2O and submitted to analysis for its tin content by HG-AFS.Under the condition of the proposed method,interferences of commonly co-existing ions and also of the organic tin compounds were eliminated.Detection limit (3S) of this method was 4.5 ng·L-1.RSD′s (n=11) found were 4.5%.Recovery over 93% was achieved.