Field performance of recently bred varieties and leading varieties of three forage species, Dactylis glomerata, Festuca arundinaced and Medicago sativa was evaluated in Japan and France, and the results revealed different aspects of plant breeding in the two countries. Japanese varieties bred in the warm region displayed a high yield in both countries and superior persistency under the humid conditions prevailing in Japan. These differences in persistency were evidenced by the larger loss of stands of French varieties in later years, caused mainly by weed invasion during summer and autumn. Japanese varieties displayed a higher competitive ability with weeds. It was concluded that through selection for higher yield and regrowth during shortday seasons under humid conditions, Japanese population acquired a superior competitive ability, and varieties bred in Japan for higher yield became persistent also as a result of adaptation to the climatic conditions of Japan. Varieties from France displayed a high resistance to rust in both countries, and evaluation in Japan confirmed the high palatability of a tall fescue variety of France. The emphasis of breeding work on forage quality in France contrasted with that in Japan and the history of forage use seemed to be an important factor for the differences.