The roots development and accumulation of saponins of a medicinal licorice Glycyrrhiza uralensis Fisch.were investigated by means of anatomic,histochemical and chemical analysis methods.The results showed that:(1)Saponins distributed mainly in the phloem parenchyma cells and ray cells of the roots.The content of total saponins in different tissues of taproot was varied.The highest one was in phloem,while the lowest in the root bark,between them was in xylem.(2)The accumulation of saponins was significantly increased with the roots growing ages.The content of total saponins in 3years roots was the highest.The results suggested that the accumulation of saponins in G.uralensis taproot was positively correlated with root secondary growth.It is like to provide a further understanding on the internal mechanism of the quality formation of medicinal licorice,and to improve the cultivation of medicinal licorice.