Yellow rose (Rosa xanthina) is a common ornamental shrub species widely cultivated in China. However, canker disease symptoms were discovered during our investigations in Beijing and Xinjiang, China. The fungal isolates were obtained from diseased barks and identified using combined methods of morphology and phylogeny based on a partial region of ITS, LSU, rpb2, tef1, and tub2 sequences. As a result, a new species of Seimatosporium named S. chinense was proposed and described herein. The new species is distinguished from its phylogenetic sister species, S. gracile and S. nonappendiculatum, by conidial characters. The present study improves the species concept in Seimatosporium and provides fundamental data for the yellow rose canker disease control in the future.