Fusarium oxysporum KFCC11363P produces four different cyclohexadepsipeptides. A cyclicpeptide synthetase gene from R oxysporum KFCC11363P, FoCPS1, was cloned and analyzed. The open reading frame of FoCPS1 consisted of 9486 bp without an intron, and the predicted protein encoded was comprised of 3162 amino acids. FoCPS1 exists as a single copy and is not present in R oxysporum strains that do not generate cyclohexadepsipeptides. Expression of FoCPS1 reached maximum at day 3 after inoculation and was not expressed well in the medium in which cyclicpeptides was not produced. FoCPS1 is comprised of two activation, three thiolation, three condensation, and one N-methylation domains. Based on the non-ribosomal code analysis and the domain arrangement, the first adenylation domain is likely to specify carboxylic acid derivatives such as hydroxyisovaleic acid or 2-hydroxy-3-methylpentanoic acid, and the second adenylation domain is likely to specify an N-methyl amino acid, such as N-methyl valine.