A method for simultaneously transmitting packets having different lengths to two or more users in a wireless communication system includes: generating the packets which are to be transmitted to the respective users; and simultaneously transmitting the generated packets to the respective users. Each of the packets contains information on the position of a symbol to which a tail field of the packet belongs, and the information on the position of the symbol to which the tail field belongs includes at least one of the maximum symbol number of the packet, the symbol number of transmission data of the packet, positional information of a last aggregated MAC protocol data unit (A-MPDU) subframe, and positional information of a null delimiter.