To explore the effect of Liangxue Huoxue Xiaoyin Tang (LHXT Decoction of Removing Heat from the Blood and Promoting Blood Flow to Eliminate Psoriasis) on serum levels of tumor necrosis factor-alpha (TNF-alpha), interferon (IFN-gamma) and interleukin-6 (IL-6) in psoriasis of blood-heat type. Blood samples from both the treatment group (N=33) and control group (N=30) were taken before and after treatment, and the serum levels of TNF-alpha, IFN-gamma and IL-6 were determined by radio-immunoassay and ELISA. The total effective rate achieved in the treatment group was 90.91%. The remarkably high serum levels of TNF-alpha, IFN-gamma and IL-6 in patients before treatment (P<0.01) were obviously decreased after one course of treatment (P<0.05) and were close to those of healthy subjects after two course of treatment (P>0.05). The data demonstrate that LHXT has the actions of reducing serum levels of TNF-alpha, IFN-gamma and IL-6 in psoriasis of blood-heat type, and may exert a pharmacological effect targeting at the cytokines.