In recent years, Software-Defined Network (SDN) and its OpenFlow-based architecture have been proposed and attracted extensive attentions from academia and industry. SDN is a novel network paradigm that decouples the network control function from the data plane by using OpenFlow technology. SDN realizes the flexible control of the network traffic, and it provides a good platform for the innovation of the applications in the core network. Thus in this paper, after introducing the SDN architecture, we construct the SDN-level network environment and implement the routing function. We deploy one controller, seven OpenFlow switches and two hosts in our SDN environment. The controller and OpenFlow switches support OpenFlow-1.0 protocol. In this network environment, we successfully implement the packet transferring from one host to the other host, and make the corresponding analysis.