A folding assembly box includes vertical corner hinge frames disposed in corners of the box, and vertical middle hinge frames disposed between the vertical corner hinge frames facing each other at both sides thereof. The vertical corner hinge frames are unfolded at an angle to form the respective corners of the box, and are hinged in the opposite direction to the direction where the vertical corner hinge frames are unfolded. The vertical middle hinge frames are unfolded together with the vertical corner hinge frames at both sides thereof, and hinged in the opposite direction to the opposite direction where the vertical corner hinge frames are unfolded. Top and bottom horizontal frames are disposed to connect upper and lower ends of the vertical corner hinge frames facing each other. Panels are inserted between the first top and bottom horizontal frames facing each other.