Abstract: As an important component of microzooplankton, marine planktonic ciliates are the key link between the microbial food web and classical food chain, playing an important role in the material cycling and energy flow in marine planktonic ecosystems. Since the 1960s, studies on the marine ciliate abundance and biomass in the sea areas of the world, especially in the temperate regions, have been performed extensively. In this paper, the horizontal distribution, vertical distribution, and annual variation patterns of the abundance and biomass of marine planktonic ciliates in the world sea areas were summarized. Generally, ciliates tend to distribute in the middle and upper water layers, their abundance and biomass are higher in the sea areas with more diet supply and higher primary production and showed a bimodal or unimodal pattern in a year, larger ciliates are more prevalent in spring than in summer, and the contribution of tintinnid to the total ciliate abundance was higher in summer or autumn.

Key words: slope aspect, slope position, species diversity, biomass, annual fine root production.