Abstract: A collapsing device for a stroller is provided, including a framework consisting of two front feet, two rear feet, a lying frame, an extended frame and an inverted U-shaped handle pivotally combined with the front and rear feet. When a pusher unit fixed on the handle is pressed, the extended frame supporting a canopy is swung down to a collapsed position to lie on the lying frame. Then, the handle is swung down, with two connecters functioning as pivots for the handle to permit the handle to disengage from the front feet in moving to the collapsed position, responsive to a contact member of each connecter respectively separating from upper ends of the two front feet.