Rural exodus has proceeded greatly during and after the period of a rapid growing economy in Japan that started in 1960s. The proportion of older men and women in agricultural workers has increased. It has been feared that Japanese agriculture may face a drastic decline in production in the near future. The purpose of this study is to observe the structural change in agriculture, relying on agricultural census data and other public statistics, and to find out who are to be the leaders of agricultural industry today. There is no doubt that the leaders chiefly consist of leading farmers. What kinds of farmers were or are to be the leading farmers, however, has often been discussed in articles on Japanese agriculture since pre-war days. The observations are summarised as follows: (1) The leading farmers were larger landowners (who also cultivated a part of their land themselves) in the Meiji era. After those landowners became rentiers, the larger ownertenants consisted of leading farmers in the Taisho and early Showa era. The function of those leaders were mainly to extend improved methods of husbandry. The improved husbandry they advocated, however, were chiefly concerned with rice farming. The category of leading farmers of this kind can not be applied to the farmers after the World War II, especially since 1960, because the specialization of farming in various enterprises has advanced and the technique and the ways of management have differed between various types of farms or between larger and smaller farms. (2) In the Agricultural Basic Law in 1961, the farmers on enlarged farms were expected to be leading farmers for future purposes and those farms were defined as “viable farms” on which the farmers could earn an income at least comparable with wages in other industries. The enlargement of the sizes of farms has not so proceeded as was expected, because ①the movement of farm workers has been largely limited to younger family members and most of smaller farms have remained as part-time farming; ②that the amount of land sold has been decreased sharply coupled with the rapid rise of land values; and @that the returns of farming have not kept up with the rising land values due to comparatively low prices of agricultural produces under the conditions of overproduction of various produces. This overproduction was accelerated by the import of grains and other agricultural produces. (3) With the increase in imported grains, domestic supply of grains has decreased. The proportion of domestic supply of grains to the total were only 45% in 1970 as compared with 82% in 1960. The Ministry of Agriculture emphasized the necessity of improving domestic supply of agricultural produces when the grain prices rose sharply in the world market in 1972. The Ministry also recognized the farmers on full-time farm households, in addition to viable farms, as leading farmers in agricultural industry, for the share of viable farms output to the total was only 30% at that time. In spite of those measures the movement of agricultural workers to non-agricultural sectors continued. The number of full-time farm households decreased from 1,630,000 in 1972 to 867,000 in 1984. (4) The shares of gross output by full-time farm households to the total were higher on intensive types of farms (dairy, pigs, poultry and horticulture). On rice farms, the share was only 30% in 1984. The enlargement of the sizes of farms is a key factor for rice farms to increase the farming returns. But it is difficult, in general, under the present conditions of a narrow land market. (5) The number of farms over 5 ha, however, tends to increase in recent years. Most of them rented in land from smaller farm households. It has been osberved that some of them are from 10 to 20 ha in scale. But these farms largely consist of many plots of land (fields) which are small in size and scattered, and it obstructs the efficient use of farm machinery and labor. Another trial of enlarging the size of operation is found in group farming. In this trial all plots of one village are usually divided into several blocks, Wheat, soybeans and, in some cases, forage crops are raised on one or two blocks and the rest are raised to rice. (6) The leaders of group farming are mostly of full-time farmers. It has been often observed, however, that some staff members of agricultural cooperatives also have performed a great part through their efforts and advices in organising those group farming. Such staff members should be included in the leaders of agricultural industry. This is a point that this study maintains. The functions of leaders have been manifold and tends to be borne by different persons (who are not necessary farmers) with the changes in agriculture especially since 1960.