The present study is intended to analyze the early response of protoplasts isolated from soybean suspension cells to electrofusion. It was observed by light microscopy that protoplasts formed a pearl chain-like structure after AC application, started to fuse after. DC pulse application and became round-shaped cells within five to fifteen minutes. Electron micrographs showed that after giving DC electric pulses, the originally smooth surface of some protoplasts became rugged. This structural change was observed mainly on the contact areas or opposite sides of two protoplasts. Then, fusion started at the narrow areas on the surface membrane of protoplasts in contact with one other. Next the fusion area increased and the cell components mixed slowly. Finally, the fusion bodies became round. Based on the above results we believe that the fusion process consists of five steps : adhesion of protoplasts, deformation of protoplast surfaces, fusion in narrow areas, progress of fusion between protoplasts and formation of round-shaped fusion bodies.