The method to detect vitamin B1 in germ-retained rice and polished rice by HPLC-UV detector was researched. The samples were extracted by 0.1 mol/L hydrochloric acid for three times in ultrasonic cleanser, and the extract solution was measured after being concentrated. The chromatographic conditions were that detection at 246nm, mobile phase was methanol:sodium acetate(0.1 mol/L) =80:20,column temperature was 30 ℃ ,current velocity was 0.9 mL/min. The result showed that coefficient of recovery of this method was above 90%, all of the RSD was less than 5%, the detection limit (S/N=3) was 0.012 μg/mL. This method was fast, easy to operate with better repeatability.