The future wireless communication networks will integrate different radio access technologies (RATs), which are referred to as heterogeneous wireless networks (HWNs). In this paper, we deal with two data oriented access networks, the Long Term Evolution (LTE) and the high speed downlink packet access (HSDPA). Assuming that the networks can support multi-homing access and the user can be served by both networks simultaneously, we propose a traffic split scheme with the aim of maximizing the throughput based on common radio resource management (CRRM). The split ratio in the scheme is dynamically adjusted under the consideration of the user's channel quality and the network load. The simulation results show that the proposed scheme can improve the throughput, also reduce the delay of the networks compared with the scheme using the fixed split ratio.