Abstract: A height-adjustable folding chair comprising a main frame, an auxiliary leg foldably connected to the main frame and a seat mounted on the main frame. The main frame has a pair of left and right poles and lateral bars bridged between the poles. The seat has hooks at rear end thereof for hooking to the lateral bar, and the seat has abutting members at portions near the rear end thereof for abutting against the poles.

Abstract: A chair with continuously height adjustable seat, comprising a frame having a pair of guide portions and a seat movable along the guide portions and capable of being fixed to the guide portions.The frame comprises an outside frame and an inside frame both of which are inverse-U shaped pipe frames, and parallel portions of their both sides serve as the above guide portions.The seat has a pair of support members of which rear portions are inserted in the gaps between the outside frame and inside frame, and each rear portion has a pair of rear stoppers having rubber-made covers and a pair of front stoppers, so that those stoppers securely grip the pipes of guide portions when user sits on the seat.The pipes in the guide portion have oval cross section longer in lateral direction.Clamping force of the stoppers is improved and right and left side stopper's group are balanced in clamping force.