Objective：To observe the therapeutic effects of Radix Astragali injection combined with Acitretin on psoriasis mice model. Methods：Effects of Radix Astragali injection combined with Acitretin on proliferation of vaginal epithelium，proliferating cell nu－clear antigen（PCNA） expression，differentiation of tail scale epidermis and plasma endothelin-1（ET-1） were assessed in mice model. Results：Radix Astragali injection combined with Acitretin had effects on all 4 indices mentioned above. Radix Astragali injection com－bined with Acitretin can significant inhibit vaginal epithelium proliferation，PCNA expression and plasma ET-1 as well as promote the differentiation of tail scale epidermis with statistical differences compared with those in control group（P<0.001）. Conclusions：Radix Astragali injection combined with Acitretin can improve and reverse psoriatic pathology model in mice，the mechanism of which may relate with the inhibition of epidermal cell over-proliferation and the promotion of granular layer formation. Its therapeutic effects may be explained by bloclking multiple pathogenetic linkages.