A SDBD plasma actuator with pulse modulation has been proposed to increase the efficiency of the performance. A flow induced in still air by the SDBD plasma actuator with pulse modulation synchronizes with modulation frequency and forms vortexes. We need to measure two dimensional velocity and vorticity, so we measured them by PIV. We compared measurement results by PIV and a hot-wire anemometer to evaluate validity of the PIV measurement. As a result, the PIV measurements are roughly valid.