Abstract: Now the SDN becomes the hot topic in the telecom world. It is based on the separation of the control plane and data plane, also introducing the programming between network and service. So SDN can promote the network virtualization and device uniformity, as help to reduce the CAPEX/OPEX and release time for new service. SDN is the key trend for the future network evolution obviously even in its early stage now. The OpenFlow, which is the typical protocol in SDN is maturing step by step with the work in ONF. Also some R&D related with SDN is in progress all over the world, indicating the right future of the SDN.