Abstract: Rubber powdery mildew caused by Oidium heveae seriously affects the rubber production and causes economic losses. Salicylic acid（SA） is an important signal molecule for disease-resistant defense responses in plant cells. Plant pathogens secrete isochorismatase（ISC） during pathogenesis, thereby ISC can inhibit the accumulation of SA in plants and affect the disease resistance of plants. In this study, we identified a gene encoding a homologous protein（OhIsc1） with a length of 693 bp, 3 introns, and a cDNA size of 600 bp encoding 199 amino acids in O. heveae genome by bioinformatics analysis. Moreover, the protein, a predicted non-classical secreted protein,had an ISC conserved domain, belonging to a family of ISC, but had no signal peptide. The cDNA sequence of OhIsc1 was obtained by homologous cloning and the pYES2-OhIsc1 vector was constructed. S. cerevisiae strain YPG30 was transformed with pYES2-OhIsc1 vector and the transformant was obtained. OhIsc1-HA was detected in the extracellular fluid of the transformant by Western blot immunoblotting, indicating that OhIsc1 can be secreted to extracellular space by yeast cells. This study confirmed that OhIsc1 was a secreted protein, which provided a foundation for its role in the pathogenesis of pathogens.