Marine planktonic ciliates are a link between microbial food web and classical food chain. They play a pivotal role in material cycling and energy flow in marine ecosystem. Since the 1970s, growth rates of marine planktonic ciliates have been studied in both laboratory and in situ. Only few laboratory studies on ciliate growth rates are available in China, and no field research has been carried out to determine the growth rates of planktonic ciliates. This review summarizes previous studies on the growth rates in both laboratory and in situ. Laboratory experiments show that the growth rates varied with food type and temperature. Under a certain temperature, ciliate would stop growing or die when food availability is below its threshold value. The growth rates could increase as food concentration increase over the threshold value, and then reach intrinsic growth rate (μ_max), stay or drop slightly at a high food concentrations. Scientists estimated the μ_max values of 34 oligotrichous ciliate species in laboratory; and the values ranged 0.1-3.05 d^-1. Feeding on a given prey, ciliate would stop growing or die at low temperature. μ_max increased linearly with temperature in the intermediate range. Higher pH will restrain μ_max. Size-fractionated seawater incubation was used to estimate in situ ciliate growth rate, from which the maximum growth rate was 3.3 d^-1. Temperature, hypoxia, and prey (bottom up control) influenced the ciliate growth rate in different regions. Planktonic ciliate production, calculated according to ciliate abundance and growth rate, was higher than planktonic copepod production in most cases.