Objective To investigate the levels of cytokines in sera of patien ts with various types of psoriasis. Methods Six cytokines, sIL-2R、 IL-2、- 4、-10、-12 and IFN-γ , were detected by sandwich ELISA in the sera from 15 patients with guttate psoriasis, 23 plaque psoriasis, 9 pustular psoriasis, 9 arthropathic psoriasis and 9 erythrodermic psoriasis. Results Significantly hig her levels of cytokines were observed in guttate psoriasis for sIL-2R (P 0.01 ), in plaque psoriasis for IL-4,-12 and sIL-2R (P 0.05 or 0.01), in pus tular psoriasis for IL-4 and-10 (P 0.05), in arthropathic psoriasis for IL -10 (P 0.01), in comparison with the controls. The levels of the six cytokine s were increased in erythrodermic psoriasis with no significant difference from the controls. The ratio of the average level of IL-4 to IFN-γ was 1.57 in pu stular psoriasis, 0.61 in plaque psoriasis, 0.30 in gutatte psoriasis, 0.24 in e rythrodermic psoriasis, and 0.02 in arthropathic psoriasis. Conclusion There is different expression of cytokines in sera of patients with various types of psor iasis.