© 2015, American Institute of Aeronautics and Astronautics Inc, AIAA. All Rights Reserved. Flow control method using direct current (DC) plasma discharge in Mach-7 hypersonic flow was investigated as a method to improve aerodynamic characteristics of hypersonic vehicles. In this work, the effect of DC arc plasma discharge was investigated to clarify its flow control effectiveness both with numerical analysis and with hypersonic wind tunnel experiments. When a plasma discharge is maintained ahead of double-wedge shaped surface that represents a body flap of hypersonic vehicles, numerical simulation based on simple energy addition model that represent plasma was conducted and it revealed that the aerodynamic force acting on the slope significantly decreases by more than 10 percent. Experimental results also suggested that the force acting on the slope decreases a lot within a very short time less than 0.1 seconds, suggesting that the present plasma discharge configuration can serve as an efficient aerodynamic control technique with a very short response time.