A novel ent-kaurane diterpenoid dimer, fritillebinide B (1) together with one known diterpenoid dimer fritillebinide A (2) were isolated from the bulbs of Fritillaria ebeiensis var. purpurea G.D. Yu et P. Li. Compound 1 has been established to be ent-3β-acetoxy-kauran-16β,17-acetal ent-16β-kauran-17(R)-aldehyde (1) by means of spectral analysis and chemical evidence.