All Japan Dockworkers' Union

The All Japan Dockworkers' Union (JDU; Japanese: 全日本港湾労働組合, Zenkowan) is a trade union representing port workers in Japan.

The union was established in 1946, and was affiliated with Sanbetsu.^[1] However, in 1950 it switched to the new General Council of Trade Unions of Japan (Sohyo).^[2] Its membership reached 28,214 by 1970,^[3] then fell to 22,124 in 1985. In 1989, Sohyo merged with the Japanese Trade Union Confederation, but Zenkowan instead opted to become independent.^[1]