The paper analyzes how Japanese group farming organizations have developed since World War II. In post-war Japanese agriculture, part-time farmers are increasing, and heirs and successors to the older farmers are leaving farms and rural areas as a consequence of rapid industrialization. About nine years after the emergence of post-war voluntary group farming, the government introduced the concept of corporate (group) farming, appealing in particular to young farmer-successors hoping that corporate (group) farming would help them get benefits similar to those offered by industries in urban areas. The study reveals that thanks to the government's special support and laws, the number of corporate (group) farming organizations has rapidly increased although it is still low as compared to the number of voluntary group farming organizations. Nowadays, however, group farming plays an important role in post-war Japanese agriculture. This paper also discusses briefly how Japanese group farming differs from, or is similar to, group farming in some other Asian countries, developed and developing.