Multi-Connectivity (MC) is a key technology in the deployment of the upcoming Fifth Generation (5G). MC means that one user can connect to a Master Evolved NodeB (MeNB) as well as several Secondary Next Generation NodeBs (SgNBs) simultaneously. According to MC, MeNB will forward a portion of traffic to SgNBs through non-ideal backhaul, while the remaining traffic will be served by itself. An efficient traffic splitting scheme has great impacts on the performance of MC. In this paper, we propose a goodput-aware traffic splitting scheme based on queuing theory and goodput model. Taking the nonideal backhaul delay as well as the buffer status of MeNB and SgNBs into consideration, the proposed traffic splitting scheme can adaptively optimize the system goodput. Simulation results verify that the proposed goodput-aware traffic splitting scheme effectively contributes to the goodput increment.