A new Rehmannia glutinosa cultivar ‘Dagang’ was bred from ‘Jihwang 1’ (check variety) seedlings by the medicinal crop breeding team of the National Institute of Horticulture and Herbal Science, RDA, in 2010. It has pink flowers, a dark brown seed coat, and a light yellow root cortex. The plant type was intermediate erect, whereas ‘Jihwang 1’ showed some drooping. The leaf shape was narrow oblong, whereas ‘Jihwang 1’ was oblong. The yield of dried root was higher than that of ‘Jihwang 1’. ‘Dagang’ showed stronger resistance to root rot than did ‘Jihwang 1’, rendering it more stable in cultivation. The regional adaptation trials were conducted at three different locations from 2009 to 2010. The average yield of ‘Dagang’ was 20.1 ton/ha, which was 14% higher than that of ‘Jihwang 1’. Also, compared with ‘Jihwang 1’, the yield of ‘Dagang’ was 1%–3% higher than that of the existing cultivars ‘Kokang’ and ‘Togang’. This cultivar could adapt to most of the cultivation areas in Korea, except for mountainous regions (Registration No. 4724).