In April 2020, a leaf blotch disease was observed on Mahonia bealeiin Nanjing, China, with an infection rate of ca. 81%. It leads to early defoliation in severe cases and affected the exploitation of its ornamental and medicinal values. Symptomatic leaves were collected from infected plants. After isolating the fungi, their pathogenicity were tested to satisfy Koch’s postulate, and based on the multigene phylogeny ( ITS, LSU, SSU, TEF1-α and β-tub) and morphology, the two isolates we obtained (SD3-6 and SD3-8 ) were identified as Botryosphaeria dothidea. This is the first report of B. dothideacausing leaf blotch of M. bealeiin China.