Abstract: Chuan Bai Zhi(Angelicae dahuricae var, Tawainiana)is a commonly used Chinese traditional medicinal herb.159 psoriatics reluctant to various modalities of therapy were treated with oral preparations of Chuan Bai Zhi(CBZ)plus black light with favourable therapeutic results.These patients were given CBZ-1 10g or CBZ-3, CBZ-4, CBZ-5 4-6 capsules by mouth, and two hours ater, they were exposed to black.light with a dose of 1.5-4.0 J/cm²,3 to 6 times a week.Among these 159 patients, the final results were 76(47.2%)fully recovered(lesions completely disappeared),36(22.0%)almost recovered(more than 90 percent of lesions disappeared),33(20.8%)had evident improvement (more than 70 percent of lesions disappeared),7(4.4%)improvement(more than 50 percent of lesions disappeared)and in 9 patients(5.6%)the result was unsatisfactory(less than 50, percent of lesions disappeared).Side-effects of the therapy were fairly xriild,manifested as trasient dizziness,nausea,discomfort of stomach,itching etc.Further treatments were not interrupted.Functional tests of liver and kidney,and routine tests of blood and urine of the patients showed no abnormalities.CBZ-3 was similar to 8-MOP in curative effect,but the side-effects of CB2-3 were milder than that of 8-MOP.The authors suggest that CBZ-3 is a valuable, preparation for treating psoriasis.