Abstract: Tripterygium wilfordii 3-hydroxy-3-methylglutaryl coenzyme-A reductase (TwHMGR) is an important regulation site in terpenoids metabolic pathway in cytoplasm which is the first speed limit enzyme of MVA pathway. In order to investigate the effects of TwHMGR on the biosynthesis of triptolide and celastrol in Tripterygium wilfordii, the overexpression of TwHMGR (OE-HMGR) was studied in this paper. We cloned the full-length of TwHMGR to construct overexpression vector by Gateway technology then delivered the expression vector into Tripterygium wilfordii suspension cells by gene gun. qRT-PCR was used to detect the expression of TwHMGR:the expression of TwHMGR was increased to 1.75 folds over the control group (empty vector:pH7WG2D) in the overexpression group. The accumulation of triptolide and celastrol in the suspension cells of Tripterygium wilfordii was detected by UPLC, revealing that:the contents of triptolide and celastrol were increased to 163.93% and 190.04% of over the control group in the overexpression group. Based on these findings, the positive effect on the accumulation of active terpenoids, triptolide and celastrol in Tripterygium wilfordii was found and the results laid a foundation of the synthetic biology research on important active terpenoids in Tripterygium wilfordii.