In Japan, adzuki bean has been produced mainly in Hokkaido particulary in Tokachi district over one hundred years. This research was conducted to clarify the production property improvement of old and new cultivars in yield and yield components in adzuki bean.Experiments were carried out at the experiment field of Obihiro university in 2000 and 2001. Ten cultivars which were chosen from Hokkaido leading cultivars from 1905 to 1996 were used. The oldest cultivars is Maruha(1905) and the latest cultivars is ...