We report a technique to simultaneously determine the local activation magnetic moment with a spatial resolution of a submicrometer scale. The local activation magnetic moment is determined from the magnetic-field dependence of the magnetization reversal at the corresponding region observed by a magneto-optical microscope system. The present method has been applied to measure the activation magnetic moment distribution of Co/Pd multilayers. It was found that the activation magnetic moment was nonuniform on a submicrometer scale and that the distribution of the activation magnetic moment enhanced with increasing the film thickness. (C) 2001 American Institute of Physics.