Slow-motion replays highlight important and exciting events in sports videos. Previous works for slow-motion replay detection, however, are usually limited to only some specific production rules such as frame repetition, special video effects and transitions. In this paper, we present a generic method for detecting slow-motion replays in sports video based on the difference of motions between slowmotion replays and normal shots within the same shot class. Experiments on different types of sports videos have verified our approach and achieve reasonable results.