The outbreak of apple scab was found on the apple seedlings growing in Korea which were imported from Marylang, U.S.A. in 1972. Symptom of apple scab is much similar with pear scab caused by Venturia pirina except that the round spot on leaves, more lesions on upper side of leaves and much severe symptoms appeared on both side of leaves. About $14\%; and ;12\%$ of plants were infected in 1972 and 1973, respectively.