Objective: To explore the relativity between cytokines such as IL-8, TNF-α, VEGF and psoriasis and the influence on its variation by ILLLI. Methods: 47 patients with psoriasis were divided into 5 groups, treated with ILLLI (1h per day, a course of treatment is 10 days), observed the variation of IL-8, TNF-α and VEGF in peripheral blood of patients with psoriasis between pre and post treatment and compared with the control. Results: 1. In each case of psoriasis, the concentration of IL-8 in blood was significantly higher than that of control group. After treatment, the concentrations of A group, B group and C group were decreased significantly, which were close to the control. The related statistical analysis showed significant difference. Among them, A group decreased most significantly; Although there is no significant difference in concentration of IL-8 of D group and E group between pre and post treatment, the trend of them became to keep decreasing. In each case of psoriasis, the concentration of TNF-α in blood was much lower than that of control group. The concentration of TNF-α in A, C, D group increased significantly as compared with pre-irradiation except that in E group. In cases, the concentrations of VEGF in blood were much higher than that of control group. In each group, there was no difference in VEGF concentration between pre and post irradiation. Conclusions: The decrease of IL-8 induced by ILLLI might be related with its immunosuppressive function. It suppressed the activity of CD4+T cell which could secrete a great deal of IL-8 and play an important role to the tache of psoriasis onset. So in the psoriasis patients who were treated with ILLLI, the production of TNF-α could be suppressed. In patients, the increasing of VEGF might be related with the increasing of IL-8. There was no difference of it between pre and post ILLLI treatment might because VEGF was not the action target of ILLLI.