Monooxygenase (MO) is a kind of enzymes that can incorporate one atom of oxygen into the substrates in many metabolic pathways.This study aimed to clone the full-length cDNA of a MO from the transcriptome data of Tripterygium wilfordii and analyze its function.Methods:The full-length cDNA of monooxygenase (TwMO) was cloned from the transcriptome data of Tripterygium wilfordii by designing specific primers.The TwMO gene was then analyzed by a series of bioinformatics analysis.Results:It showed that the full length of TwMO cDNA was 2193 bp encoding 507 amino acids.The theoretical isoelectric point was 8.84 and the molecular weight was about 55.20 kDa.Sequence alignment and phylogenetic analysis demonstrated that TwMO had relative close relationship to MO from other species of plants.The relative expression level of TwMO after MeJA inducing was up-regulated and highest at 48 h,which suggested its regulatory role in special metabolites biosynthesis.Conclusion:This work laid the foundation for further studying the function of this monooxygenase in Tripterygium wilfordii.