Abstract: This paper reports a diatom assemblage found by the author from the Upper Tertiary continental strata in Shangdu County in Niemongol Autonomous Region and Dun- hua County in Jilin Province of China. The diatom assemblage in Shangdu County com- prises 4 new species and 2 new varieties: Tetracyclus ellipticus var. ovalifolium Li;  Tetra- cyclus ellipticus var. rostrata Li;  Tetracyclus jaoi Li;  Tetracyclus navicularis Li;  Tetracyclus shangduensis Li and Tetracyclus sinensis Li. From the Miocene of Dunhua County;  JilinProvince are recorded 2 new species: Tetracyclus dunhuanensis Li and Tetracyclus ovaliformis Li.