A backflow preventing apparatus for a scroll compressor is disclosed, in which a check valve is hinge-coupled to a valve seat, or is coupled to a valve seat so as to be elastically opened and closed. The check valve is opened and closed by a pressure difference and its own weight or elasticity, thereby having a quick response speed. The check valve prevents discharged refrigerant from backflowing, thus enhancing efficiency of the compressor. Further, since the check valve when opened is prevented from colliding with a valve housing by a valve stopping surface or a retainer, discharge noise from the compressor is reduced.