A shoe tree includes a front piece, a heel piece, a coupling device adjustably coupled between the front piece and the heel piece, and two side pieces coupled to the front piece, and movable and expansible and adjustable relative to the front piece, for suitably forming various curvatures or contours or shapes for the shoes. The side pieces are pivotally coupled to the front piece with a pivot axle. The side pieces each includes a spring member engaged with the front piece, to bias the side pieces away from the front piece. The side pieces may be guided to move relative to the front piece. The coupling device includes a link having a latch adjustably coupled to the front piece.