Abstract: The ¹³C NMR chemical shifts of a series of kauran tetranuclear diterpene compounds which were published in the past years were reviewed, their regularity and characteristics were summarized. It was found that C16, C17 and C18 seem to be substituted by hydroxyl group and their chemical shifts were affected by the configuration.We also found that C19 tend to be substituted by carboxyl group.
This characteristic was applied for confirming the structure of a new compound-ent-16β,17,18-trihydroxy-kauran-19-oic acid. Its structures was verified by IR, MS and ¹H NMR.

Key words: Kauran tetranuclear diterpene, ¹³C NMR, Ent-16β,17,18-trihydroxy-kauran-19-oicacid