The metabolism of [14~textrmC ] ~textrmGA12 in the Chinese yam (Dioscorea opposita Thunb. var. Tsukune) was examined to determine the identification of endogenous gibberellins. [14~textrmC ] ~textrmGA12 was metabolized to ~textrmGA53 , ~textrmGA44 , ~textrmGA19 , ~textrmGA20 , ~textrmGA1 , ~textrmGA8 , ~textrmGA15 , ~textrmGA24 , ~textrmGA9 , ~textrmGA36 and ~textrmGA4 . Radioactivity of GAs in non C-13 hydroxylation route was five-fold higher than that of early C-13 hydroxylation in analyzed GA-metabolites. Radioactivity of ~textrmGA4 was always four times higher than that of ~textrmGA1 at every feeding time. ~textrmGA1 radioactivity has always a lower level to below 200 DPM. The major pathway of endogenous GA metabolism in seedlings of the Chinese yam might be the non C-13 hydroxylation pathway.