AbstractWe have already reported on reconstructions of the symmetrical and nonsymmetrical electric field vector distribution using the Kerr electrooptic effect and our unique reconstruction method, a modified computed tomography technique. This reconstruction technique gives an electric field map, that is, the strength and the direction of the electric field vector, on any plane. For the reconstruction of one field vector distribution, it was necessary to measure the light intensity twice while changing the optical axis of optical wedges. Moreover, the intensity measurement must be carried out at many points around the electrode system. Therefore, considerable time was required to measure the electric field distribution. We therefore developed a simultaneous three‐direction optical measurement system with three optical systems combined with the two‐beam method. Using the new measurement system, we measured the electric field distribution on planes in a sphere‐to‐sphere electrode system. It took about 0.1 second to measure the light intensity data for the reconstruction. © 2002 Scripta Technica, Electr Eng Jpn, 139(1): 9–15, 2002; DOI 10.1002/eej.1141