A wireless communication apparatus, a method thereof and a wireless communication system employing the same. The wireless communication apparatus for transceiving data wirelessly, includes a transceiving unit for transmitting and receiving data to and from an external apparatus, a buffer for temporarily storing data to be sent, the buffer having an indicator for indicating the existence of data, and a controller for checking the indicator of the buffer after the data has been sent to a destination wireless communication apparatus via the transceiving unit, and for confirming that the data is successfully sent to the destination wireless communication apparatus if there is no data in the buffer. According to the wireless communication apparatus, the method thereof and the wireless communication system applying the same, the successful transmission of the data would be easily checked.