This study aims to elucidate the underlying molecular mechanisms of artemisinin accumulation induced by cadmium (Cd).The effects of different Cd concentrations (0,20,60,and 120 μmol/L) on the biosynthesis ofArtemisia annua L.were examined.Intermediate and end products were quantified by HPLC-ESI-MS/MS analysis.The expression of key biosynthesis enzymes was also determined by qRT-PCR.The results showed that the application of treatment with 60 and 120 μmol/L Cd for 3 days significantly improved the biosynthesis of artemisinic acid,arteannuin B,and artemisinin.The concentrations of artemisinic acid,arteannuin B,and artemisinin in the 120 μmol/L Cd-treated group were 2.26,102.08,and 33.63 times higher than those in the control group,respectively.The concentrations of arteannuin B and artemisinin in 60 μmol/L Cd-treated leaves were 61.10 and 26.40 times higher than those in the control group,respectively.The relative expression levels of HMGR,FPS,ADS,CYP71AV1,DBR2,ALDH1,and DXR were up-regulated in the 120 μmol/L Cd-treated group because of increased contents of artemisinic metabolites after 3 days of treatment.Hence,appropriate doses of Cd can increase the concentrations of artemisinic metabolites at a certain time point by up-regulating the relative expression levels of key enzyme genes involved in artemisinin biosynthesis.