An air blower device of an air-conditioning system for a vehicle including: a blower case including a duct part having an indoor air inlet and an outdoor air inlet, an air blowing part connected with an inlet of an air-conditioning case and a connection part for connecting the duct part with the air blowing part, the connection part having an insertion part of which the certain area is hollowed; an indoor and outdoor air converting door disposed inside the duct part of the blower case to open and close the indoor air inlet and the outdoor air inlet; an air blower is disposed inside the air blowing part of the blower case to forcedly blow air; an electric dust collector located at the connection part through the insertion part of the blower case; and a cover for opening and closing the insertion part of the blower case.