Abstract: The fresh hog lung was homogenated and centrifugated with 35%～55% saturation ammonium sulfate fraction. Thenby using of Sephadex G-100 gel filtration and DEAE Sephadex A-50 anion exchange chromatogram column, pure ACE (Angio-tensin I-Converting Enzyme) showed as a single band by SDS-PAGE test and gave an apparent molecular weight about 185kD.The result was 347.09U ACE was obtained from 200g hog lung tissue with specific activity 29.029U/mg and activity recovery12.53%. Using Lineweaver-Burk method, the Michaelis-constant of hog lung ACE was 3.168mmol/L and Vmax 6.165nmol/min.After two months conserving, the test proved that the activity of the ACE was kept steady.

Key words: hog lung, angiotensin converting enzyme, gel filtration, anion exchange