To observe the acute toxicity of recombinant porcine interferen-alpha (IFN-alpha) in mice and thus provide a basis for the clinical safety. [Method] According to the principles of acute toxicity, all the mice were divided into two major groups (intraperitoneally injected group and intramuscularly injected group) respectively at high dose, moderate dose and low dose. And the normal control group was also set up. Within 14 d after administration, the behavior of mouse and the degree of toxicity were continuously observed. The hematological indexes and biochemical indexes of blood were detected to obtain the preliminary toxicity data of the recombinant porcine IFN-alpha. And at the end of the experiment, mice were sacrificed for autopsy. [ Result] There was not significant difference in external performance, behavioral characteristics, body temperature, weight, pathological anatomy of visceral organs, hematological indexes and biochemical indexes between the experimental groups and the control group. [ Conclusion] The highest dose of porcine interferon (5.0 x 10s IU per mouse) in this experiment or the dose lower than this dosage should not have significant toxic effects on mice, and the recombinant porcine IFN-alpha is safe in clinical application.