Abstract: RP-HPLC was applied to the determination of t-butylhydroquinone (t-BHQ),which is added to food-stuffs as antioxidant.An appropriate quantity of sample was dissolved in n-hexane,and its t-BHQ was extracted with methanol.which was introduced into the HPLC instrument for separation and determination.The symmetry shield RP C18 was used as stationary phase,and a mixed solution containing CH3OH and 0.001 mol·L-1 H3PO4 in the ratio of 60 to 40 by volume (pH 5.0) was used as the mobile phase.UV detection at wavelength of 280 nm was adopted.Buffer solution prepared from 0.001 mol·L-1 HOAc and 0.001 mol·L-1 H3PO4 was used to control the acidity of the mobile phase.Linear relationship between peak area and concentration of t-BHQ was obtained in the range of 0.010 07-0.402 8 g·L-1,and the detection limit (S/N=2) was found to be 0.020 14 μg.In the test for precision,the RSDs obtained in the between-day and within-day measurement of retention time or of peak area were all less than 3.4%.Recoveries in the range from 91.8% to 94.0% were found in the test for recovery.Only 6 min were required for a whole analysis.