Abstract: The crude enzyme of the arginine deiminase (ADI) from Enterococcus faecalis SK32.001 had been purified and the basic properties of ADI were investigated. The result of SDS-PAGE showed that ADI was purified to homogeneity level by fraction precipitated with ammonium sulfate, Hi Prep Q FF 16/10 and Sephadex G-75 gel filtration chromatography. The molecular mass of the purified ADI was estimated to be about 42 ku. The optimum temperature and p H of the purified ADI were 50℃ and 6.5, respectively. ADI activity kept stability under the temperature of 30⁴0℃ and at p H range of 5.5⁷.5. Among the metal irons, different concentrations of Zn2+could obviously affect the activity. 1mmo I/L Zn2+, 10 mmo I/L Co2+, 10 mmo I/L Ca2+and 10 mmo I/L Mg2+were the effective promoter while 10 mmo I/L Cu2+had poor improvement in the activity. The Michaelis constant was 1.33 mmo I/L and the maximum velocity was 2.41μmol/min.