A study of radiating of underwater sound by a vibrating body is provided. Of all forms of radiation known, sound travels through the sea the best. In the turbid, saline water of the sea, both light and radio waves are attenuated to a far greater degree than is that form of mechanical energy known as sound. Because of its relative ease of propagation, many studies to apply underwater sound to a variety of purposes have been made. However most of them were discussed from the point of view that the underwater sound technology is the tool to transmit information, so they were studies on the sound propagation at relatively long ranges. On the other hand, the naval-architects are interested in the sound field at short range, for they have to arrange the acoustic equipments in the ship which have many noise sources. This paper presents the theory and the numerical calculating manner of sound propagation in near field.