Abstract: An adjustable supporting device for a display panel includes a stationary supporting member having a tube portion disposed uprightly on a base portion, and a movable rod member movably extended into and in friction engagement with the tube portion. The rod member includes a rod body coupled to a display panel and formed with an inner recess, and a mounting cap mounted on the rod body and cooperating with the inner recess so as to confine a receiving space. A biasing member has a straight coupling portion coupled to the tube portion of the stationary supporting member, and a spiral portion connected to the coupling portion and disposed in the receiving space. The mounting cap is formed with a positioning unit for positioning the spiral portion of the biasing member in the receiving space.