Abstract: Scorpion toxin BmK AngM1 has been reported to have a strong analgesic effect. However, its anti-inflammatory activity was unknown. In this study, the recombinant BmK AngM1 (rBmK AngM1) was expressed in Escherichia coli BL21 trxB (DE3). The purified rBmK AngM1 was obtained efficiently through the IMPACT^TM-TWIN system. The anti-inflammatory activity of the recombinant protein was investigated. In order to improve the anti-inflammatory activity of rBmK AngM1, the potential active sites (Y5, Y42, R58) were substituted with different amino acids. The results showed that rBmK AngM1 and its mutants all have significant anti-inflammatory activity. The activities were significantly increased in the single mutant R58N and mutants Y5F/R58N, Y42F/R58N over the wild type protein. The data suggest that position 58 in BmK AngM1 plays a functional role in the anti-inflammatory activity. This study lays a foundation for the protein engineering design of BmK AngM1 to improve its pharmacological activity.