Provided is a knee joint supporter which can improve the stability of the knee joint, reduce the wearer's fatigue and reduce the load on the patellar tendon. The knee joint supporter (10) comprises a first anchor section (2) formed by wrapping one end of a tubular knitted fabric around the wearer's thigh to tighten said part with the tubular knitted fabric, a second anchor section (3) formed by wrapping the other end of the tubular knitted fabric around the wearer's lower thigh to tighten said part with the tubular knitted fabric, and a substantially U-shaped knitted supporting section (4) being joined to the first anchor section (2), covering the wearer's patella region and thus supporting the wearer's patella, wherein the stretch resistances, in the circumferential direction of the tubular knitted fabric, of the first anchor part (2) and the second anchor part (3) are larger than the stretch resistance, in the circumferential direction of the tubular knitted fabric, of a base fabric section (1), and the stretch resistance, in the length width direction (L) of the tubular knitted fabric, of the supporting section (4) is larger than the the stretch resistance, in the length width direction (L) of the tubular knitted fabric, of the base fabric section (1).