MIURAAbstruct-The Japanese domestic experimental mobile satellite system (EMSS) has been studied to establish high qnality channels for small vessels with compact and low-gain antennas. The present international maritime satellite communication system (INMARSAT) has also been studied for the next generation to extend services for small ships, for which the present ship terminals inclnding the antenna systems are too large and too heavy. By using a low-gain antenna, however, mdtipath fading caused by sea reflections wiU become a serious problem in designing the new system. To take effective countermeasures to the fading effect, it is verg important to get a better knowledge of the fading phenomena caused by sea reflections.From a standpoint of maritime satellite communications, experiments measuring the amount of fading were performed nuder various sea conditions and in two frequency bands. The wave height, which is considered the most important experimental parameter, was measured objectively by a wave rider buoy. The experimental results show that the amonnt of fading depends on a wave height and radio frequency and, as the most interesting result, as a wave increases above a certain level, the amount of fading decreases. These results are also discussed theoretically.