Abstract: A supporting device for a telescope during observation includes a cylindrical housing of a reflexive telescope and an eye-viewing unit fixed on a side surface of the front end section of the cylindrical housing, a grip fixed on a lower surface of the front end section of the housing, and a shoulder stand fixed on a lower surface of a rear end section of the cylindrical housing. The height of the shoulder stand is adjustable. In using, the shoulder stand is placed on a shoulder, and a user holds the grip with one hand, with the height of the shoulder stand adjusted to permit the eye-viewing unit aligned to the level of an eye of the user. Thus the telescope can be stabilized for observing in spite of turning together with the body for tracing a moving object.