Abstract: While there was acid scarlet GR （AS GR）,the polarographic method of determining bovine serum albumin （BSA） with high sensitivity was reported in this article. In Tris-HCl buffer solution with pH value being 7.43,AS GR had a sensitive reduction peak at-0.88 V （vs.SCE）. After BSA was added,the reduction peak potential of AS GR was shifted positively and the peak current was changed. When the concn. of BSA was 0.35 times higher than that of AS GR,the peak current of AS GR was decreased; when the concn. of BSA was 0.35 times lower than that of AS GR,the peak current of AS GR was increased. Under the chosen experimental condition,the second order derivative peak current of reduction peak of AS GR showed good linear correlation with the concn. of added BSA in the range of 1.0 × 10-9 ～ 9.0×10-7 mol/L. This method could be applied in the quantitative analysis of trace BSA.