A method and apparatus for transmitting and receiving data are disclosed. The method for transmitting data, comprising encapsulating one or multiple media access control protocol data units (MPDU) as a group media access control protocol data unit (G-MPDU) based on a length of the group media access control protocol data unit G-MPDU; fragmenting a current MPDU according to a residual length to obtain a fragmented MPDU when the residual length is insufficient to encapsulate the current MPDU; encapsulating the fragmented MPDU to the G-MPDU; and transmitting the encapsulated G-MPDU. The method ensures a high data transmission rate and does not wasting excess time to execute the fragmentation processing. The method also ensures a high resource utilization rate, utilizing fully the remaining length of the data unit.
