Provided is a method of dividing a payload intra-frame for improving throughput of a carrier sensing multiple access/collision avoidance (CSMA/CA) wireless communication network. The payload intra-frame dividing method includes a data frame dividing step and a physical layer frame generating step in which a physical layer receives a plurality of data frames from an upper layer within a range of the maximum data frame length the physical layer can transmit and transmits the data frames as a single physical layer data frame. Furthermore, an acknowledge (ACK) frame is provided, which can minimize the deterioration of throughput even when a data frame, which has been divided into a plurality of data frames and transmitted as a single data frame, is required to be re-transmitted because an error is generated in the data frame.