Aspartate-β-decarboxylase is an enzyme that catalyzes the decarboxylation of L-aspartate to produce L-alanine. The gene coding and expressing this enzyme was cloned from Alcaligenes faecalis. In this study, the vector pETDuet-1 was used to recombinant express the aspartate-β-decarboxylase in Escherichia coli BL21(DE3). Several influencing factors of the enzyme reaction, such as pH, pH stability, temperature, thermal stability, concentration of substrate, were all investigated. The results indicated that the recombinant aspartate-β-decarboxylase was successfully expressed and the reaction was optimal at pH 6.0 and 45癈. The Km and Vmax values of aspartate-β-decarboxylase were 0.72 mmol/L and 10.52 mol/(L?min?g). 10 ml of 0.2 mol/L phosphate buffer included 0.1 g wet cells, 0.2 mmol/L 5'-pyridoxal phosphate, and 0.2 g L-aspartate, after 15 hours, the mole conversion rate of L-aspartate was up to 99%.