An acetabular cup assembly for an artificial hip joint includes an acetabular cup comprising a seating recess, a female taper formed on an inner wall, protrusion recesses formed to communicate with the seating recess and insertion recesses each positioned inside a corresponding one of the protrusion recesses； and a bearing comprising a male taper on an outer circumference thereof, protrusions inserted into the protrusion recesses, and insertion protruding portions each formed on a corresponding one of the protrusions, the insertion protruding portions being inserted into the insertion recesses. A polyethylene bearing can be firmly fixed to the acetabular cup. When a ceramic bearing made is inserted into the acetabular cup, the area where the bearing adjoins the acetabular cup is increased, thereby preventing the ceramic bearing from being broken. Since no groove is formed along the entire circumference of the acetabular cup, the strength is increased.
