To explore the effect of Liangxue Huoxue Xiaoyin Tang (LHXT 凉血活血消银汤 Decoction of Removing Heat from the Blood and Promoting Blood Flow to Eliminate Psoriasis) on serum levels of tumor necrosis factor-α (TNF-α), interferon (IFN-γ) 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-α, IFN-γ 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-α, IFN-γ 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-α, IFN-γ and IL-6 in psoriasis of blood-heat type, and may exert a pharmacological effect targeting at the cytokines.