During the 5 years period(93-197) of Seoul racecourse Thoroughbred racing, 2i963 holies took an active part in Seoul Racecourse and 61,181 horses entered the racing.400 horses(305 : 1 time, 76 :2 times, 19 :3 times, total : 514 cases) had bled(EIPH) from their nostils after their races. Incidence of bleeding horses from the 21963 racehorses was 13.5%, and incidence of bleeding cases from the 61,181 horses was 0.84%. The average racing frequence (1.05 times/1 month) of bleeders was more than that(0.8 times/1 month) of total race-horses. There was tendency to higher incidence of bleeding at older in age, female in sex, England/ Ireland horses in origin, higher grade in performances heavier in body weight increased, larger in weight to be carried, mid or longer in racing distance, handicap race, spring in season. Relationship did not exist between bleeding and respiratory disease. These results suggested that frequent entering into the race should be controlled. And body weight regulation with conditioning is recommended far reducing incidence of EIPH. It is supposed to prevent bleeding that decrescent performance horses should not be entering long distance or handicap race.