A light input-adjustable window shade includes a supporting unit having a main rod and two sliding rods. The two sliding rods are respectively slideably mounted to two ends of the main rod. A positioning seat is fixed to an end of each sliding rod distant to the main rod. Each sliding rod has a coupling portion. A spool is rotatably mounted to the positioning seats of the supporting unit. A shade body includes a first periphery fixed to the spool and a second periphery. The shade body is coiled around the spool. A weighting unit includes a rod body comprised of an inner rod and a movable rod. The movable rod is slideably mounted to one of two ends of the inner rod. The shade body is wound around the rod body. The second periphery of the shade body is fixed to the coupling portions of the two sliding rods.