DNA fragments homologous to chitin synthase gene were amplified from the genomic DNA of Beauveria brongniartii by PCR using degenerate primers. Cloning and sequencing of the PCR-amplified fragments led to the identification of a gene, designated BbCHSl. Comparison of the deduced amino acid sequence of BbCHSl with those of other Euascomycetes revealed that BbCHSl is a gene for class II chitin synthase. The Blastp search of the deduced amino acid sequence of BbCHSl displayed the highest rate of similarity, 95.8%, with CHS2 of Metarhizium unisopliae. Phylogenetic analysis of the amino acid sequences confirmed the taxonomic and evolutionary position of B. brongniartii, which was previously derived by traditional fungal classification based on morphological features.