Ostracod assemblages from Nam Co were analyzed to design a training set for reconstructing Holocene water level changes in this saline lake. A transect consisting of nineteen surface sediment samples taken from 2 m to 64 m water depth was used to analyze Recent ostracod taphocoenoses. The samples contained abundant ostracods of up to about 1000 valves per gram sediment but display low species diversity. The six documented species are, in descending order of dominance, Leucocytherella sinensis Huang, 1982,? Leucocythere dorsotuberosa Huang, 1982, Fabaeformiscandona danielopoli Yin & Martens, 1997, Ilyocypris cf. mongolica Martens, 1991, Candona candida (OF Müller, 1776) and Limnocythere inopinata (Baird, 1843). L. sinensis and? L. dorsotuberosa together composed about 90% of the associations.? L. dorsotuberosa showed high morphological variability. Leucocythere postilirata Pang, 1985 is regarded here as a morphotype of? L. dorsotuberosa with pronounced posterior, medio-ventral and anterior carinae as protruding foldings of the shell. This form occurred below the thermocline (20–30 m water depth) and became more abundant with increasing