Two-in-one bearing cup system can use ceramic liner and polyethylene liner in a combined way. The polyethylene liner applies UHMWPE (Highly cross-linked UHMWPE), which has proved to be 94% less in wearing than the conventional PE liners under the in vitro conditions. The sufficient thickness (>6mm) of UHMWPE provides the strengthened resistance against wearing. In terms of cup and ceramic insertion, not only the self-locating function which uses taper locking to make the insertion easier, but also the stable locking mechanism can help provide the excellent congruency as well as the stable fixation for push-out, rotation and tilting. The innovative stem neck design has increased ROM to prevent impingement and dislocation.