This research was conducted to investigate the group and individual behavioral patterns of thoroughbred mares which are important for raising race-horses, in paddoks (pregnant) and pastures (nursing). In a group of nursing mare, eating 62%, standing resting 31%, drinking 3%, lying resting 1%, walking 1% and nursing 2% were observed, although no running was observed. Average time spent on individual behavior of mares (3 heads) was eating 295 min (55%), standing resting 193 min (36%), walking 18 min, drinking 18 min (3%), nursing 13 min (2%), lying resting 6 min (1%). Average 11 times of grooming, 2 times of urinating, and 1 time of feces were observed for mare in pasture. 48% of standing resting, 44% of eating, 2% of lying resting, 4% of walking, and 2% of drinking were revealed for pregnant mares in paddock. Average individual behavioral pattern of pregnant mares (3 heads) was 52% of eating, 40% of standing, 6% of walking, and 2% of drinking. Average 15 times of grooming, 1 time of urinating, 3 times of feces, 1 time of fighting, and 2 times of rolling were observed for pregnant mares in paddock. For moving patterns, pregnant mares were inclined to concentrate on where the nearby paddok is close to.