The 2-Dimensional soft X-ray behavior during ECR heating have been examined in the GAMMA 10 tandem mirror. The peak position shifts several cm during the ECRH period, and it is found the peak position of the soft X-ray is rotating around the center axis of the vessel and its direction is same as that of E×B drift. In high power heating case, the oscillation of the peak position, decrease of the diamagnetism and line density are observed. The radial ion current measured by the ion sensitive probe increases depending on the ECRH power together with increase in the radius of the SX-peak rotation.