Abstract:13C NMR signals of twelve natural triterpenes of olean-12-enes, erythrodiol (1), primulagenin A(2 ), barrintogenin C(3 ), azukisapogenol (4 ), soyasap-ogenol B (5 ) and C(6 ), hederatriol (7 ), gypsogenin (8 ), quillic acid methyl ester (9 ), epigypsogenin (10), gypsogenic acid (11) and medicagenic acid (12), have been assigned, and substituent effect of oxygen-containing groups in them has been discussed.