The invention discloses a semi-condylar artificial knee joint, which includes a femoral prosthesis and a tibial prosthesis, and the cross-section of said tibial prosthesis is of a kidney-like type. The tibial prosthesis is disposed at one side of the tibial plateau intercondylar eminence and is located below the femoral prosthesis. The artificial knee joint further includes a locating pin for fixing the tibial prosthesis. The bottom surface of said tibial prosthesis is provided with a prosthetic notch, and below said tibial prosthesis is provided with a tibial notch. Said prosthetic notch corresponds to said tibial notch, and together forming a limiting hole for accommodating the locating pin. The cooperation between the locating pin and the limiting hole can ensure relative position stability and balance between the tibial prosthesis and the tibial plateau intercondylar eminence. When two semi-condylar (medial and lateral) artificial (half) knee joints are installed in one knee joint at the same time, the limiting holes in the two artificial (half) knee joints connect and share a locating pin to form a complete combined full knee joint. Said tibial prosthesis includes an upper gasket and a lower gasket, and the lower gasket is provided with an elastic subassembly.