Abstract: AIM: To sutdy the non-basic constituents of the Chinese herbal drug “Ebeibeimu”, the bulus of Fritillaria ebeiensis G.D.Yu et G.Q.Ji, in order to appraise its quality systematically. METHODS: MeOH extraction and silica gel column chromatography were to isolate pure compound, its structure was determined with various spectral analysis including 2D-NMR techniques and chemical methods. RESULTS: A diterpenoid has been isolated from the EtOAc fraction of the bulus of Fritillaria ebeiensis, growing in the Suizhou disrtict of Hubei province, China. It was established as ent-kauran-16β,17-acetal ent-16β-kauran-17(S)-aldehyde (1) on the basis of physicochemical and spectral data and chemical synthesis. CONCLUSION: Compound 1 is a novel acetal diterpenoid dimer with ent-kaurane skeleton, named fritillebinide A.