After studying materials collected by the Institute of Oceanology, Academia Sinica and some foreign specimens preserved in the Natural Museums of Tientsin and Dairen, we came to the conclusion that the total number of 43 species of Olividae previously reported from the coast of China by different authors is far more than what actually exists. As various distinct species differ only in color and pattern and not in morphological features of specific significance, we consider them as being synonymous with one another. As a result, the total number of species of Olividae of the China coast is reduced by 1/4. All of the species studied can be found in the South China Sea but only three in the East China Sea and two in the Yellow Sea. Among those reported, five species deserve further discussion.