Objective The aim of this study was to establish rat models of immunosuppression and immune hyperfunction. Methods Sixty-four SPF Sprague-Dawley rats were randomly divided into groups A, B, and C. All rats were immunized with intraperitoneal injection of 100 μg ovalbumin (OVA). The group A was used as control. At 6 hours after immunization, the rats of group B were injected with different doses of cyclophosphamide (Cy) at different time points. The rats of group C were injected with Cy in different ways at 3 days before immunization. Results Immunosuppressed rats were successfully induced by Cy (125 mg/kg or 100 mg/kg) at 6 h after immunization and also by injection of 225 mg/kg Cy at 3 days before immunization with ovalbumin. Small dose (20 mg/kg) of Cy injected once or a smaller dose (5 mg/kg/d) injected once a day for consecutive 3 days can also result in immune hyperfunction. Conclusions Rat models of immunosuppression and immune hyperfunction are successfully established, which provide methodological and data support for establishment of such animal models and useful reference for related research.