A new diterpenoid glucoside, 15,16-dihydroxy-4-formyl-neo-clerodane-3,13 (Z)-dien-17-O-β-Dglucopyranosyl (1), was isolated from Sheareria nana S. Moore. The structure was elucidated by spectroscopic data. 1 was evaluated for cytotoxic activities against human endometrial carcinoma cells (Ishikawa and ECC-1). The results suggested that 1 exhibited moderate cytotoxic activity against Ishikawa and ECC-1 cell lines with IC50 values of 6.6 ± 0.2 and 12.1 ± 0.1 μM for 24 h respectively, whereas 1 showed no cytotoxicity against a human hepatocyte cell line. Thus, 1 was a potential choice for the treatment of endometrial carcinoma. [ABSTRACT FROM AUTHOR]