A reversed phase HPLC method was developed to determine the major components of Psoralea corylifolia, psoralen, isopsoralen, bakuchiol, and corylin. Quantitative analysis of the above compounds was performed by C-18 column using a gradient solvent system of acetonitrile and water with UV detection at 310 nm. The comparison of contents of psoralen, isopsoralen, bakuchiol, and corylin in psoraleae semen and the processed psoraleae semen was also investigated. In result, processed psoraleae semen showed more amounts of psoralen, isopsoralen, and corylin with 1.6, 4.3, and 1.3 mg/g, respectively, except bakuchiol (66.98 mg/g) while psoraleae semen showed 0.53, 1.56, 1.0, and 76.3 mg/g of psoralen, isopsoralen, corylin, and bakuchiol, respectively.