Abstract: The present disclosure is related to an automatic device for applying tapes along the edges of a carton for sealing purpose in general, and more particularly to an automatic tape-applying device which can effect the operation of adhering a partially placed tapes, along the edges of a carton, smoothly to the surface thereof, the carton having been transmitted by conveyor belts via a tape-applying means. The final adherence of the tape to the surface of a carton to be sealed is carried out by two brush members, one short and one elongate; the short brush is actuated to repeatedly move horizontally in a pre-set distance by an air-actuated cylinder so to adhere the tape placed at the corners of the carton to the surface thereof, and the elongated brush is actuated to repeatedly move up and down so to complete the process of the final adherance of the tape fully to the surface thereof automatically.