Abstract: A knee joint rehabilitation apparatus for a wheelchair includes a rehabilitation apparatus frame having a height corresponding to a length of each of legs of a patient sitting on the wheelchair; an upper leg support disposed at an upper end of the rehabilitation apparatus frame and supporting upper legs of the patient thereon while the patient is sitting on the wheelchair; a lower leg support pivotably connected to the upper leg support, wherein the lower legs of the patient are seated and supported on the lower leg support; and an exercise control unit disposed on the rehabilitation apparatus frame and configured to allow the lower leg support to pivot around a connection portion between the lower leg support and the upper leg support such that the patient performs rehabilitation exercise of the knee joint thereof while sitting on the wheelchair.