In order to elucidate the function of the catalase (CAT) gene (RsCat) in Rhizoctonia solani Kühn AG-1 IA,the causal agent of rice sheath blight,the gene was cloned with PCR and RT-PCR.Result of bioinformatics analysis showed that the full-length DNA and cDNA sequences of RsCat gene were 1 814 bp and 1 395 bp,with an open reading frame (ORF) encoding 464 amino acids. Result of conserved domain analysis showed that the RsCat protein has the domains of catalase-like super family with catalase-related immune-response. Result of phylogenetic tree analysis showed that the RsCat gene in different anastomosis groups (AGs) of R. solani has a high sequence homology. Result of quantitative real-time PCR (qRT-PCR) analysis showed that RsCatgene expression was induced by catechol. The expression levels of RsCat gene were up-regulated with the increase of catechol concentrations,whereas the activity of catalase (CAT) decreased with the increase of catechol concentrations,indicating that there is no corresponding between the transcriptional expression of RsCat gene and CAT activity. The RsCat gene may produce post transcriptional or post translational modifications.It will provide a foundation for further studying the regulatory mechanisms of melanin formation and ROS metabolism with RsCat of R. solani AG-1 IA.