Twelve outlined osrracod assemblages from Kimmeridgian of the late Jurassic to Albian of early Cretaceous in age can be recognized in Northeast China, in which three types of sedimentary facies, i. e. the marine, the marine-terrestrial transitional brackish and the inland lacustrine facies are included, while the latter is the most developed. The distribution horizons, characteristics and epochs of the ostracod assemblages are chiefly elucidated in the present paper. Twelve outlined osrracod assemblages from Kimmeridgian of the late Jurassic to Albian of early Cretaceous in age can recognized in Northeast China, in which three types of sedimentary facies, ie the marine, the marine-terrestrial transitional brackish and the inland lacustrine facies are included, while the latter is the most developed. The distribution horizons, characteristics and epochs of the ostracod assemblages are chiefly elucidated in the present paper.