Five strains of A type Cl. perfringens of different titres of toxicity (BP6K, SR-12, 2836, 2910, 1) possessed a distinct activity of ornithine transcarbamylase. In cells the maximal activity of the enzyme was observed within 3-5 hrs of growth of the culture. The enzyme was partially purified and some of its physico-chemical properties were studied. Ornithine transcarbamylase was termostable. Monoiodine acetate, p-chloromercurybenzoate, semicarbazide, Hg-2+, Cu-2+ and Fe-3+ inhibited the enzymatic activity, but Mg-2+ and Ca-2+ activated the enzyme. Ornithine transcarbamylase was shown to be active in wide region of pH: from pH 6.0 to pH 9.0 and higher. Two peaks of the enzyme activity were observed: the first (a more distinct one) at pH 8.6-8.9 and the second, smaller,--at pH 6.5-6.7.