Abstract: Changes in principal root exudates of referenced 3-year-old ginseng plants in different hydroponic trial treatments one-Hoagland nutritional solution (CK) and nutritional solution free B, Mn, Zn and Fe elements, respectively were measured and compared. The results show that in all 5 treatments including CK, 23 ~ 30 components are detected, including alcohol, fatty acids, fatty acid esters, phenolic acids and their derivatives, aldehydes, etc. further analysis shows that except for the 20 components detected in root exudates of the 5 treatments, compared with ck, components of other groups decrease and fatty acids and phenolic acids components increase under microelement deficiency treatments. The results imply that microelement deficiencies have significant effect on the composition of ginseng root exudate.