Abstract: 【OBJECTIVE】To find out the effects of different trace element on the photosynthesis and secondary metabolites of Leonurus japonicus Houtt.;【METHOD】Pot experiments were carried out, different trace element were sprayed on the leaf during the developmental stage of medicines, and the leaf photosynthesis characteristids and contents of stachydrine of Leonurus japonicus Houtt.in different fertilization treatment were calculated and compared;【RESULTS】The result indicate that trace element of different concentration could facilitate the photosynthesis and stachydrine contents of Leonurus japonicus Houtt. in various degree. Among them, the effect of normal concentration of Mn,Zn and Fe were more distinguished, they elevate the stachydrine contents 96%，62%and 57%more than the control group. And stachydrine content were significant correlated with the max-photosynthesis;【CONCLUSION】It illustrate that trace element can impact the content of the end product by regulating the metabolism of physiology and the precursor and kinase of the secondary metabolite.