Abstract: Compounds 1-8 belong to oleanane type triterpenoids with similiar structures, ¹³C NMR spectra of β-amyrin (1); 3-oxo-olean-11,13(18)-diene (2); 3β-hydroxy olean-11,13(18)-diene (3); 3β,24-dihydroxy-olean-11,13(18)-diene (4); 3,11-dioxo-olean-12-ene (5); 3-oxo-olean-9(11),12-diene (6); 3-oxo, 11α-hydroxy-olean-12-ene(7); 3β,11α-dihydroxy-oean-12-ene-(8) were studied, and spectral assignments were carried out. The assignments were checked by their DEPT spectra. They were divided into three guoups, 2-4 in the first guoup; 1,5,7,8 in the second and 6 in the third. This paper investigated and discussed mainly the changes of their ¹³C NMR chemical shift values which were taken place by the structural characterization and substituted groups. Some significant results of chemical shifts in relation to structures were obtained.

Key words: ¹³C NMR, Oleanane type triterpenoids, Substituted groups