A method of providing a point-to-multipoint service in a mobile communication system and transmission controlling method thereof are disclosed, by which a better quality of a point-to-multipoint service can be provided in a manner of coping with time-variable channel situation variable adaptively. In a mobile communication system providing a point-to-multipoint service, the present invention includes the steps of receiving data for the point-to-multipoint service from a base station, measuring a reception quality for the received point-to-multipoint service data, and transmitting reception quality information for the point-to-multipoint service data to the base station.