A data flow control apparatus of a mobile terminal that performs reverse communication from a high speed communication device to a wireless network. An Rm interface unit receives data from the high speed communication device and buffers the received data in a byte stream format. An Operating System (OS) device driver includes a first packet buffer queue for reading and storing data buffered in the Rm interface unit upon receipt of an interrupt from the Rm interface unit. The OS device driver manages a first linked list for managing data stored in the first packet buffer queue. A Um interface unit includes a second packet buffer queue having the same buffer structure as that of the first packet buffer queue. The Um interface unit manages a second linked list for managing data stored in the second packet buffer queue, converts the data stored in the second packet buffer queue into a frame format, and transmits the frame-format data to a wireless network. A packet processor de-links an address of the data stored in the first packet buffer queue from the first linked list, and links an address of the de-linked data to the second linked list, to deliver the data from the first packet buffer queue to the second packet buffer queue. A controller controls data flow of the first packet buffer queue.