The present invention relates to a knee protector. The knee protector has a structure that has an increased supporting strength capable of further enhancing the knee protective effect, and also, the supporting strength can be conveniently lessened by a user so as to exercise more comfortably. The knee protector comprises: a protector configured to surround and compress a knee for knee protection； and supporting rods, each in the shape of a long rod, and vertically inserted into both side ends of the protector to support the knee area. In particular, the protector comprises: a protection band made of a flexible material and formed to be thin and flat, to surround the knee in a cylindrical shape； a fixing portion for fixing the protection band； and a supporting rod-accommodating portion formed to match the width of the supporting rods, so that the supporting rods can be vertically inserted in a lateral end of the inside of the knee and a lateral end of the outside of the knee when the protector surrounds the knee. More specifically, the supporting rods are provided with a plurality of rotating flexible bars stacked in front and back, in double layers, wherein the centers and both lateral ends of the rotating flexible bars form rotating connection portions connecting the front and back rotating flexible bars, and wherein the rotating connection portions at the both lateral ends have a structure in which the front and back rotating flexible bars are connected in a zigzag pattern so as to be stretchable when pushing and pulling the both lateral ends of the supporting rods. The knee protector according to the present invention securely supports the femur and tibia through a strong support strength and compression, thereby minimizing the damage to the anterior cruciate ligament and the posterior cruciate ligament； can effectively prevent twisting of a cartilage connecting one bone to another bone； and when bending and stretching the knee, can significantly reduce damage by
