In order to develop a hairy vetch (Vicia villosa Roth) cultivar which is suitable for cropping after the rice harvest in middle and northern regions because the cultivar can stably pass the winter season and produce much green manure, the National Institute of Crop Science developed the ‘Ontobi’, an elite cultivar through the method of line breeding after having selected good plants with superior growth rate which were derived from the germplasm ‘Ch4 (introduced from China)’. As main characteristics, ‘Ontobi’ has vivid green leaves during the blooming period and its stem hair’s density is high, and its blooming period is May 15 on average nationwide, and its average blooming period is 5 days later than that of ‘Cheongpoongbora’ the check variety. The Ontobi’s overwintering rate is 87% on average, showing 2% higher than that of the check variety, and its dry matter yield is 5.44 ton/ha on average, showing 17% more than that of the check variety, and its nitrogen content is 172kg/ha on average, showing 13% more than that of the check variety. ‘Ontobi’ can be cultivated in every region nationwide having its average lowest temperature in January is over -15°C.