In formic acid medium at pH 2.8-3.6, antimony (III) alizarin comiplexan complex shows an zdsorption single sweep derivative polarographic wave at about-0.54v (vs. S. C. E.).The height of the wave is proportional toantimony concentration between 0.01 µg/ml to 0.4 µg/ml.Down to 0.005 µg/ml antimony can be determined. The optimum condition for determination of antimony is 2-4 % HCOOH，and 2.10-5一4·10-5 M alizarin complexan at pH 2.8-3.6. Many metallic ions except tin (IV)，selenium (IV) and chromium(VI )，do not interfere. Chromium ( VI ) and selenium(Iv)can be reduced by adding ascorbic acid before extracting antimony with benzene. Some an ions such as chloride, bromide,nitrare etc., do not interfere, but succinic acid increases the wave height by 18%.