The national breeding program and network system of timothy in Japan started at the Hokkaido Prefectural Kitami Agricultural Experiment Station in 1964. It is recognized that the station is located at a favorable site for timothy breeding from the viewpoint of its environmental conditions. The breeding resources have come from Hokkaido Local, a well-adapted ecotype, as well as from 97 exotic varieties from 19 countries. Evaluation on the breeding populations was made in relation to their diversifications of heading dates, yielding abilities, resistance to diseases, regrowth abilities, winter hardiness and others. During the past 25 years, four cultivars, i.e. Senpoku, Nosappu, Hokushu and Kunpu, were registered and recommended.