Abstract: Effects of Molybdenum, Boron, Manganese and Zinc on accumulations of several secondary metabolites in Glycyrrhiza uralensis Fisch. roots were investigated under the field foliage spraying with 0, 0.5g/L，1g/L and 1.5g/L. The results show that the contents of glycyrrhizic acid and liquiritin in roots of Glycyrrhiza uralensis Fisch. are significantly related to Mn, Zn and Mo application levels. The glycyrrhizic acid contents in roots of Glycyrrhiza uralensis Fisch under the sprays of 0.5g/L，1g/L and 1.5g/L Mn and Zn , 1g/L and 1.5g/L Mo to the Glycyrrhiza uralensis Fisch. leaves are significantly increased. The additions of 0.5g/L，1g/L and 1.5g/L Mo and Zn, 1.5g/L Mn induce significant increases of liquiritin contents in roots of Glycyrrhiza uralensis Fisch. In accordance with changes of the glycyrrhizic acid and liquiritin contents, the polydaccharide contents in roots of Glycyrrhiza uralensis Fisch. are significantly related to 1g/L and 1.5g/L Mn and 1g/L Zn. These results indicate that spraying Mo, B, Mn and Zn could increase total flavonoid content. It is concluded that external Molybdenum, Manganese and Zinc with moderate and high concentrations might have up-regulative effects on quality of Glycyrrhiza uralensis Fisch.