Objective: To study the immunomodulatory and antioxidant effect of Rosa roxburghii & edible fungus fermentation broth(REFB) on immunosuppressive mice. Methods: Immunosuppressed mice models were established by intraperitoneal injection of cyclophosphamide. Mice were randomly divided into 6 groups: normal control， model control， positive control， and low， middle， and high dose (3.9， 7.8， 15.6 mL/kg bw) REFB groups. REFB was gavaged for 30 days， and body weight was recorded daily. At the end of the experiment， the immune organ index was determined， the proliferation of T and B lymphocytes was measured by the CCK-8 method， the differentiation of spleen lymphocytes was detected by flow cytometry， the level of spleen cytokines was determined by ELISA， and the level of antioxidant capacity of the liver and thymus tissues was determined using the antioxidant kit. Results: Compared with the model group， all the REFB groups had significantly higher immune organ index (P<0.05)， increased proliferation rate of T lymphocytes (P<0.05)， and promoted differentiation of spleen lymphocytes (P<0.05). Gavage of REFB could increase the spleen level of IL-4， IL-6， and TNF-α， reduce that of IL-10， while significantly increase the liver and thyme levels of superoxide dismutase (SOD)， catalase (CAT)， glutathione peroxidase (GSH-Px) and reduce that of malondialdehyde (MDA) (P<0.05). Conclusion: REFB could effectively alleviate the inhibitory effect of cyclophosphamide on immune function and enhance antioxidant function in immunosuppressive mice.