Method and apparatus for transmitting sidelink data in communication system

A first user equipment (UE), comprising:

• a processor,
• wherein the processor causes the first UE to:
• transmit, to a second UE, first sidelink control information (SCI) including resource allocation information through a physical sidelink control channel (PSCCH);
• and
• transmit, to the second UE, second SCI including information used for determining whether a sidelink communication in a sidelink resource allocated by the first SCI is stopped or not, through a physical sidelink shared channel (PSSCH) scheduled by the first SCI,
• wherein, when it is determined that the sidelink communication is not stopped based on the second SCI, the sidelink communication is performed based on the second SCI associated with the first SCI in the sidelink resource allocated by the first SCI;
• and
• when it is determined that the sidelink communication is stopped based on the second SCI, the sidelink communication of the second UE is not performed in the sidelink resource allocated by the first SCI.