b Institute of Materia Medica, Chinese Academy of Medical Sciences, Beijing 100050, China c Pharmaceutical Department of Dali College, Dali, Yunnan 671000, China Further investigation on the leaves of Isodon sculponeatus afforded two new ent kaurane diterpenoids, sculponeatins J and K . Their structures were elucidated on the basis of their spectral properties, as well as X ray crystallographic analysis. The cytotoxicities of these two new compounds against human tumor cells K562 and T24 were also tested, and sculponeatin J showed significant inhibitory effects with IC 50 values less than 1.0 μg/mL. b Institute of Materia Medica, Chinese Academy of Medical Sciences, Beijing 100050, China c Pharmaceutical Department of Dali College, Dali, Yunnan 671000, China Further investigation on the leaves of Isodon sculponeatus afforded two new entaurane diterpenoids, sculponeatins J and K. The structures were elucidated on the basis of their spectral properties, as well as X ray crystallographic analysis. The cytotoxicities of these two new compounds against human tumor cells K562 and T24 were also tested, and sculponeatin J showed significant inhibitory effects with IC 50 values ​​less than 1.0 μg / mL.