An embodiment of the present disclosure provides a method for performing sidelink (SL) communication based on physical sidelink control channel (PSCCH) by a first apparatus. The method may include transmitting a first sidelink control information to a second apparatus through PSCCH, and transmitting a second sidelink control information to the second apparatus through physical sidelink shared channel(PSSCH) related to the PSCCH, wherein the first sidelink control information includes at least one reserved bit reserved for use.