This report concerns an attempt to immunize experimental animals with Taiwanese snake venoms which were inactivated by dihydrothioctic acid. Reports on surveys of field trial of prophylactic shots with toxoided venom in habu-infested area is also added here. Five kinds of venom were collected, milked and freeze dried from snakes at Taipei of Taiwan. At first, two kinds of Agkistrodon acutus and Bungarus multicinctus were inactivated by dihydrothioctic acid and injected into rabbits and mice. Those immunized animals were challenged intramuscularly by each kind of untreated venom for the test of antigenicity. Blood levels of antibody of immunized animals were also investigated. The results showed that hemorrhagic effects of venom of A. acutus were prevented in considerable degree in immunized rabbits, although antibody of sera of immunized animals were not so high as antivenin for treatment. Antilethal activity of mice which were treated by venom toxoid of B. multicinctus increased definitely. In the next, immunological relationship of venom of T. mucrosquamatus, T. stejnegri and T. elegans were investigated. Rabbits were immunized with each of those venom toxoid, and then crossly challenged by those venom respectively. The results indicated that those venoms were immunologically correlated with each other. Finally, polyvalent toxoid of venom of T. mucrosquamatus, T. stejnegri and A. acutus was also proved to be good antigenic in rabbits by the same method. Analysis of results of current immunization program from 1965 to 1967 suggested that victims who received toxoided venom previously recovered without severe local lesion.