A high speed operation of a multidither adaptive optical system (MAOS) with a ninesegmented adaptive mirror and real-time compensation of dynamic phase fluctuation has beendemonstrated. Experimental results are as follows: (1) A high speed operation of MAOS withan indicial response time of 55 ms has been achieved with a new type of wavefront controlmethod by using the saturation characteristics of a photo-detector (2) Dynamic CO2-laserwavefront distortion with a spot dancing of 47 μrad (rms), induced by two gas burners, hasbeen compensated in real time by the high-speed operation of the control system. The laserbeam was then converged within a nearly diffraction limit, improving the laser peak intensity by afactor of 2.8 with a Strehl Ratio of 0.8. A frequency spectrum measurement of the detectorsignal also confirmed that the turbulence spectrum component was automatically suppressed.