Objective To establish a RP-HPLC method for the determination of psoralen and isopsoralen in Qianggu Capsules.Methods An Agilent C18(4.6 mm?250 mm,5 ?m)column was used.The methyl-water(45:55) was used as the mobile phase.The flow rate was 1.0 mL?min-1.The determination wavelength was at 246 nm.Results The linear range was 0.08～0.80 ?g,for psoralen,r=0.999 8,the average recovery rate was 99.3 %,RSD=1.4 %(n=5),and for isopsoralen,r=0.999 9,the average recovery rate was 98.5 %,RSD=0.8 %(n=5).The linear equation was Y=7 365.9X-102.7 for psoralen and Y=7 556.0X-65.3 for isopsoralen.Conclusion The method is simple,reliable,accurate,and can be applied to control the quality of Qianggu Capsules.