A new gibberellin C20H26O6, tentatively named “bamboo gibberellin”, was isolated from water extract of bamboo shoots (Phyllostachys edulis) through successive purification proce-dures: countercurrent distribution, charcoal column chromatography, and silicic acid adsorp-tion and partition chromatography. Its structure was established as lα-methyl-4aβ-fromyl-7β-hydroxy-8-methylenegibbane-lβ, 10α-dicarboxylic acid (VI) from analysis on infrared, NMR and mass spectra of its methyl ester.