To investigate the effect of methyl jasmonate (MeJA) on the accumulation of alkaloids in Coptis chinensis and to provide a basis for further research on the molecular regulation mechanism of MeJA on the biosynthesis pathway of alkaloids in C.chinensis.Methods:The leaves of C.chinensis seedlings were sprayed with 100 μmol/L MeJA and sampled at 0 h,24 h,48 h,72 h,and 96 h after treatment.High-performance liquid chromatography (HPLC) was used to determine the content of jateorhizine,epiberberine,coptisine,palmatine chloride,and berberine hydrochloride in C.chinensis seedlings.Results:MeJA treatment for 48 h could significantly increase the content of jateorhizine,epiberberine,coptisine,palmatine chloride,and berberine hydrochloride in C.chinensis seedlings,with the highest growth rate.Among them,coptisine showed pronounced response to MeJA,and the content of coptisine treated for 48 h was 3.15 times that of control group.After MeJA treatment for 96 h,the content of alkaloids in C.chinensis seedlings showed a downward trend.Conclusion:The accumulation of alkaloids in C.chinensis seedlings could be significantly promoted by applying exogenous MeJA in a short time.