The genus Neotrionymus Borchsenius comprises five species in China, N. cynodontis, N. guandunensis, N. monstatus, N. yunnanensis and N. chinensis sp. nov., which collected from Beijing, Shanxi and Shandong under the leaf sheath of species of Poaceae. This new species is similar to N. kerzhneri Danzig, but can be distinguished by with a large, quadrate (longer than width) or sometimes hour-glass shaped circulus, presence of tubular ducts in median area of thorax on dorsum and venter, presence of translucent pores on apical part of hind tibia and the distribution of trilocular pores not only in cerarii, but also on lips of ostioles and near spiracles. A key to species of genus Neotrionymus in China is also given.