To provide a radio base station apparatus, a communication system, a communication control method, and a communication control program capable of stabilizing communication by suppressing increase in transmission delay along with data forwarding.

A radio base station apparatus 101 comprises: a transfer control unit 15 for, when handover operation of a radio terminal apparatus from the radio base station apparatus 101 to another radio base station apparatus is executed, performing a transfer operation to transfer to another radio base station apparatus above-mentioned an object packet being a packet addressed to the radio terminal apparatus received from a host network; and a speed control unit 21 for restricting the transmission speed of the object packet from the host network to the radio base station apparatus 101 to be slower than a reference speed.