Objective:To further study the pathophysiological function of human Api6 fusion protein expression using a prokaryotic expression system.Methods:Api6 cDNA was inserted into ppSUMO vector to form recombinant plasmid ppSUMO-Api6;recombinant plasmid ppSUMO-Api6 was transformed into prokaryotic expression host E.coli Rosetta;prokaryotic expression method was optimized to induce expression of recombinant protein Api6 in different conditions of E.coli density,temperature,IPTG concentration and induction time;recombinant protein Api6 was identified by Western blot.Results:The recombinant plasmid ppSUMO-Api6 was successfully constructed;the recombinant protein Api6 was successfully induced,and the expression of recombinant protein ppSUMO-Api6 from the prokaryotic expression system was optimized in the condition of OD600=0.5~0.8,16℃,0.5 mmol/L IPTG and 16 h induction.Conclusion:Recombinant plasmid ppSUMO-Api6 was converted into the prokaryotic expression host E.coli Rosetta to get the recombinant strain ppSUMO-Api6-Rosetta.Recombinant protein ppSUMO-Api6 was expressed using a prokaryotic expression system at the optimal expression conditions.