Abstract: 【Objective】 The aim of this project is to clarify the pathogen of Dianthus chinensis leaf spot in Shihezi area and control the disease. 【Methods】 Using conventional organic law, 8 representative strains were selected and their pathogenicity was determined by mycelium patch and spray method. The morphological and rDNA-ITS regions, histone 3 and β- tubulin sequences were compared and analyzed to establish a multi-gene combined phylogenetic tree to determine the classification status of pathogens. 【Results】 Morphologically, the conidium was similar to Alternaria nobilis. The sequence analysis of rDNA-ITS and β-tubulin of 8 isolates were more than 99.0% homologous to the reported phylogeny of Alternaria nobilis in GenBank. 【Conclusion】 Combined with the morphological characteristics and molecular biological results, the pathogen causing the Dianthus chinensis leaf spot is identified as Alternaria. nobilis in Shihezi area.