In order to express soluble matrix protein M of infectious hematopoietic necrosis virus （IHNV-M）from Escherichia coli（E. coli）and to analyze its immunogenicity，a prokaryotic expression plasmid was constructed and named as pMAL-c2x-m，the expression conditions was optimized and then MBP-M fusion protein was purified. The purified protein was identified by Western blot and DDA，and then was used to immunize BALB/c mice，and the mouse antiserum was identified by Western blot，whose titer was determined by indirect ELISA. The results showed that soluble MBP-M protein was obtained from E. coli，and its relative molecular mass was about 64 kDa as expected；the expression level of MBP-M protein in supernatant was higher when IPTG was 0.5 mmol/L and the bacteria solution was induced at 25 ℃ for 12 h；as identified by Western blot，MBP-M protein could specifically react with mouse antiserum，but failed with negative control serum；and the titer of serum antibodies reached 1:25 600 by indirect ELISA. In conclusion，the immunogenicity of the obtained MBP-M protein was good，which laid a foundation for future researches and development of genetic engineering vaccines of IHNV.