Abstract: To identify the pathogen causing spot blight of tobacco leaves in Tianlin County, Guangxi, the pathogens were isolated from typical diseased leaves and the pathogenicity of the isolate was determined by mycelium inoculation. The isolate was cultured on PDA and V8 media and its morphological characteristics were observed, and the rRNA-ITS and TUB2 sequences of the isolate were jointly analyzed for molecular identification. The results showed that the representative isolate was pathogenic to tobacco leaves, it could not produce conidia on PDA medium, but could form pycnidia and conidia on V8 medium. The pycnidia were nearly spherical with a diameter of 70-150 μ m. The conidia were single-cell, colorless and oval in shape with the average size of 7.1 μ m × 2.7 μ m. Blastn alignment and phylogenetic tree analysis of rRNA-ITS and TUB2 sequences of the representative isolate indicated that its similarity with Stagonosporopsis caricae was 99.61% and 100% respectively, and the isolate belonged to the same branch with S. caricae. Combined with pathogenicity and morphological characteristics, the pathogen of tobacco spot blight in Guangxi was identified as S. caricae.