Oxalate decarboxylase was expressed and characterized in this paper.After induced by IPTG,820 U/g(wet weight) of oxalate decarboxylase was obtained,and the enzyme was purified 2.07 fold by metal chelate affinity chromatography with a yield of 60.38%.The enzyme had an optimum temperature between 50 and 55 ℃,and optimum pH at 3.5.Addition of EDTA or Fe2+ would activate oxalate decarboxylase,but addition of Mn2+ would inhibit the enzyme.Under condition of pH4.0,37 ℃,the enzyme's Km was 14.53 mmol/l with Vmax=133.33 U/mg.