Abstract: A guide roller of a tape traveling system of a video tape recorder and the like for changing the direction of travel of a magnetic tape and regulating the heightwise position of the tape during its travel including a roller body of a diameter not constant but smoothly varying axially thereof for exerting on the traveling tape a force tending to shift the tape axially. The guide roller has a flange at the top and the bottom of the roller body having a tape guide surface for contacting the edge of the tape which is not perpendicular to the axis of the roller body but convex as viewed from the respective end of the roller body, to prevent the edge of the tape from striking the edges of the flanges. The roller body may be conical at its outer peripheral surface and at the tape guide surface of each flange.