An artificial joint includes a first joint assembly and a second joint assembly. The first joint assembly is adapted to be connected to a first bone and has a first contacting surface, wherein the first contacting surface includes a first convex arc surface, a second convex arc surface, and a third convex arc surface. The second joint assembly is adapted to be connected to a second bone and has a second contacting surface, wherein the second contacting surface is in contact with the first contacting surface and includes a first concave arc surface, a second concave arc surface, and a third concave arc surface, and the first concave arc surface, the second concave arc surface, and the third concave arc surface respectively correspond to the first convex arc surface, the second convex arc surface, and the third convex arc surface.
