Abstract: The molybdo-phosphorus blue-photometry was applied to the determination of 1,3-dihydroxyacetone (DHA) in acidic glycerol solution.Based on a systematic study on the conditions of the color reaction,the amount of the color reagent (a mixed solution of molybdic acid and phosphoric acid) used was 2.0 mL per 50 mL of reaction solution,and the reaction mixture was heated for 15 min in a water bath at 100 ℃.Beer′s law was obeyed up to 0.60 g of DHA per liter of solution,corresponding to the linear regression equation Y=2.308 X-0.025 9 (r=0.995 8).DHA itself acted as a reductant for the molybdo-phosphate in the color reaction.The presence of small amounts of GALD,GLYA,HYPA and etc in the sample solution showed no significant interferences to the determination of DHA.