An improved and relatively rapid procedure is developed for isolation and purification of a new antitumor enzyme L-lysyl-alpha-oxidase from Trichoderma sp. The method involves four steps, instead of six steps described previously, with a yield of 22.4%. The purified enzyme preparation was homogeneous as shown by polyacrylamide gel disc electrophoresis and ultracentrifugation. Physico-chemical and antitumor properties of the enzyme are under study.