A traffic control method and apparatus for solving service quality degradation caused by traffic overhead in a specific node, on which traffic is concentrated in the specific node because of traffic congestion in a software defined network (SDN) environment. A traffic control method to be performed by an SDN controller of an SDN environment includes: collecting real-time traffic state information of a network; detecting traffic overhead of at least one node on the basis of the collected real-time traffic state information; determining whether network resources are available to the at least one node where the traffic overhead is detected; and changing a service level agreement (SLA)-based bandwidth allowable capacity with regard to the at least one node in accordance with available network resources.