A robot joint driving apparatus is smoothly operated without generation of backlash. A robot includes the robot joint driving apparatus. The robot joint driving apparatus includes an internal gear having a ring shape, a main pulley arranged at the center of the internal gear and connected to a power source, first and second pinion gears provided at both sides of the main pulley and engaged with the internal gear, first and second pulleys respectively fastened to the first and second pinion gears, first and second belts respectively connecting the main pulley and the first and second pulleys, and tension adjustment units to adjust tensions of the first and second belts.