Abstract: Traditional cloud computing service chain consists of intelligent terminals， internet and cloud datacenter，is inefficient for latency sensitive applications． MEC ( Mobile Edge Computing) pushs compute power，storage power，and network resources to the edge of the Internet to improve service speed for users and terminals． However，MEC can only manage compute resources and storage resources． MEC is combined with SDN ( Software-Defined Networks) for the sake of collaborative management of compute，storage and network resources． The state-of-the-art MEC scenarios and MEC improvement researches are investigated． A MEC-SDN system architecture is proposed in terms of MEC，SDN and cloud datacenter． The latest researches on MEC system evaluation are concluded in terms of application task，communication overhead，compute overhead and resource allocation． Finally，several encouraging areas of MEC-SDN in the future are shown．

Key words: mobile edge computing, software defined networking, system performance measurement, performance evaluation