In order to establish the chemical standards for the quality control of ginsentgextract, an approach for the assay of sapogenin contents in the part of main roots and fibrous side roots was performed by combination of preparative thin layer chromotographic procedure and vanillin-$H_{2}SO_{4}$ color reaction. The contents of dammarane aglycones as funcction of dammarane glycosides in 80%-EtOH extracts were analyzed by the method from the main roots and fibrous side roots of Korean ginseng grown for 4-6 years. The differences by their grown ages in the contents of dammarane glycosides, in the ratio of panaxadiol to panaxatriol contents, and in the mounts of 80% EtOH extract were not significant in the parts of main roots and fibrous side roots of Korean gingeng. Differences due to the part for medicinal uses were highly significant in all parameters mentioned, showing following results ; in the main roots ; 80% EtOH extract, 12.7-15.7 % : the ratio of aglycone composition, 0.955-1.012 : dammarane glycoside (as diglucoside bases), 1.537-1.863 ; in fibrous isde roots ; 80% EtOH extract, 26.0-26.02% : dammarane glycoside, 4.767-5.641 : the ratio, 1.456-1.50.