〔Abstract〕 An imiquimod(IMQ)-induced psoriasis mouse model was established to evaluate the model and explore the effect of gender on IMQ-induced mouse psoriasis model establishment. Half of male and female BALB/c mice were randomly divided into normal control group,model group 1(male) and model group 2(female),and IMQ was applied to the back skin of mice to establish a mouse psoriasis model. The psoriasis area and severity index(PASI) was scored daily for mouse skin. The pathological changes of skin were observed by HE staining. The thymus index and spleen index were calculated. The expression of proliferating cell nuclear antigen(PCNA) was detected by immunohistochemistry and the expression of involucrin was detected by immunofluorescence. Compared with the control mice,IMQ-induced male and female mice showed scaly,erythema and thickening and continued to deteriorate,and the PASI score also showed the same results. HE staining found that compared with control mice,the epidermis of IMQ-induced male and female mice were thickened(P<0.001),telangiectasia and inflammatory cell infiltration were observed in the superficial epidermis. Parakeratosis was observed in the stratum corneum and the granular layer became thinner or even disappeared. The acanthosis was thick,and epidermis extended downward. The spleen index of IMQ-induced mice increased(P<0.001),and there was no significant difference in spleen index between male and female mice. The expression of keratinocytes in IMQ-induced male and female mice increased(P<0.05) and there was abnormal differentiation. There was no significant difference in the expression of PCNA and involucrin between male and female mice. The IMQ-induced mouse psoriasis model has many similarities with human psoriasis,and gender has little effect on the establishment of IMQ-induced mouse psoriasis model.