This paper describes a new Cymbella species from Lake Fuxian, Yunnan Plateau, China, based on both light and scanning electron microscopical investigations. The species, described as Cymbella fuxianensis Y.Li & Z.Gong sp. nov., has dorsiventral valves with a strongly arched dorsal margin and a ventral margin with a slightly gibbous central part. It has a narrow axial and central area with a lateral raphe that becomes filiform near the proximal and distal ends with indistinct stigmata on the ventral side of the central nodule. A comparison with similar Cymbella species is briefly discussed.