Psoriasis is a common inflammatory disease of the skin marked by excessive scaling associated with inflammation, affecting 1-2% of the population. Although their etiologies remain unknown, the finding of CD4+ and CD8+ lymphocytes at sites of psoriasis has led many reports to hypothesize that psoriasis is a T lymphocyte-mediated disease directed against unknown autoantigens. The oriental medicine understands the cause of psoriasis as low humidity of skin tissues and functional deteriorations of the liver and lung. Gami-Yunbueum (GY) is a mixture of two previous prescription, which were used to the protection of liver and lung. We had prescribed the GY to the three psoriasis patients for 11 weeks and examined the effectiveness of the GY by PASI (Psoriasis Area and Severity Index) score. In our experiment, GY improved the symptoms of psoriasis in all cases. These results indicated that GY can apply to the treatment of psoriasis. Furthermore, the process for treatment of psoriasis is possible to provide humidity to skin and control the functions of liver and lung.