In this paper, the air flow around a blunt flat plate with a rounded leading edge has been experimentally examined with and without the presence of a PLASMA ACTUATOR. Tests have been conducted with Reynolds numbers ranging from 104 to 105. Significant phenomena in this flow field is the flow separation at the leading edge of the body, which called separation bubble. There are two considerably dimensionless parameters in this experiment. One of them is the leading edge radius ratio to body thickness and other one is the ratio of maximum velocity induced by PLASMA ACTUATOR to free stream velocity. Geometries with the values of R/D=0, 1.16, 2.16, 4.16 were tested. For each geometry, the effectiveness of PLASMA ACTUATOR on the separation bubble is studied in different values of velocity ratio. The results show that, the effect of PLASMA ACTUATOR for the geometry with sharp edge (R/D=0), is negligible, while in geometry with rounded edge, the PLASMA ACTUATOR has significant effect on the separation bubble domain. This effectiveness is enhanced, by increasing of leading edge radius and velocity ratio, so that in rounded edge geometry (R/D=4.16) length of separation bubble is reduced about 75%.