Abstract: Ciliated protozoa are an important and abundant component of aquatic ecosystems. Our knowledge on their distribution and the species inventory in South China Sea is still limited. Six free-living marine haptorid ciliates, Phialina salinarum Kahl, 1928, Lacrymaria marina Kahl, 1933, Pseudotrachelocerca trepida (Kahl, 1928) Song, 1990, Chaenea vorax Quennerstedt, 1867, Cyclotrichium cyclokaryon Meunier, 1907, and Didinium gargantua Meunier, 1910, isolated from the coastal waters (salinity 25‰—32‰) of the Daya Bay (114°34'E, 22°36'N), South China, were investigated using live observation and protargol impregnation methods according to Song and Xu 1999. All of these six species were firstly reported from the South China Sea. Based on the Daya Bay populations, much more information particularly with respect to their cortical granules, cell colour, infraciliature and other morphological features in vivo as well as original morphometric data were provided. Compared with related Yellow Sea and Bohai Sea species, some variable characters of these species were recorded. As a new contribution, present paper firstly disclosed another type of cortical granules of Lacrymaria marina and found the Daya Bay population of Cyclotrichium cyclokaryon having more somatic kineties than the Qingdao population. Meanwhile, this work indicates that there is a confirming support of evidence for the haptorid ciliates recognized at the coastal waters of the Daya Bay. A particularly fruitful line of investigation on the high biodiversity haptorid ciliates may be the exploration in these habitats from the South China Sea.