Particle image velocimetry is adopted to measure the jet flow induced by surface dielectric barrier dis-charge（SDBD）plasma at air pressure of 7 kPa

the spatial distribution of the plasma induced body force is calculat-ed by using Navier-Stokes equations in accordance with the velocity field

and the influences of the electrode width and the gap width between electrodes on such induced body force and induced velocity are studied. Experimental re-sults prove that larger body force and induced velocity could be obtained if wider encapsulated electrode is used. As the gap width increases

the body force and velocity field increase firstly and then decrease

and the airflow accelera-tion distance becomes longer. There is an optimal value of the electrode width ratio as well as the gap width. It is con-cluded that the best control effect can be obtained with the electrode width ratio of 0.56 and the gap width of 6 mm.