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 includes a first anchor section formed by wrapping one end of a tubular knitted fabric around the wearer's thigh to tighten it with the fabric, a second anchor section formed by wrapping the other end of the fabric around the wearer's lower thigh to tighten it with the fabric, and a substantially U-shaped knitted supporting section joined to the first anchor section, covering the wearer's patella region and thus supporting the wearer's patella. In the circumferential direction of the fabric, the stretch resistance of the two anchor parts are larger than the stretch resistance of a base fabric section. In the length width direction of the fabric, the stretch resistance of the supporting section is larger than the stretch resistance of the base fabric section.