Through determining the contents of secondary metabolites(active constituents)in Eucommia ulmoides Oliv.(Duzhong)leaves, it is found that secondary metabolites appear dynamic accumulation trend. \ \ Variance analysis of the contents of secondary metabolites is notable in different clones.The result illustrates that the inheritable gene is an important factor in regulating the formation of secondary metaboiltes. \ \ In the growth season of Duzhong leaves, the contents of chlorogenic acid and aucubin are ...