From 2019 to 2020, a serious leaf disease was found in Hunan Province including Chenzhou, Yongzhou, Xiangxi and Changde. Symptoms displayed as round or irregular brown spots, with irregular concentric pattern and yellow-green halo and later the infected leaves were easy to rupture and perforate. The pathogen was confirmed to be Rhizoctonia solani Kola via tissue isolation, morphological observation, molecular identification and Koch’s Postulates. On this basis, a direct PCR method for detection of tobacco target spot was established using the specific primers Rs-1F and Rs-1R designed based on the rDNA-ITS sequence of the pathogen. Using this method, the pathogen fungus could be detected directly from the disease spots on tobacco leaves.