Acid-stable α-amylase is widely used in fermentation industry.In order to highly express acid-stable α-amylase gene,a recombinant vector containing no signal peptide of acid-stable α-amylase gene from Bacillus amyloliquefaciens was constructed followed by transformation into Bacillus subtilis WB600 host.The highest activity of recombinant acid-stable α-amylase was 1230 U/mL under the condition as follows: OD600 of the initial bacteria was 0.8 and final concentration of IPTG was 0.9 mmol/L,and the cell suspension was cultured for 6 hours after addition of IPTG.As the recombinant Bacillus subtilis WB600 secreted few other proteins except the targeted acid-stableα-amylase,it showed obvious advantages in amylase production.