A new protoberberine, named 8,13-dioxo-14-butoxycanadine (1), was isolated from the bark of Phellodendron chinense Schneid. In our continuous search for new and bioactive components from Chinese traditional medicine, we report the isolation and structural elucidation of this new compound. Its structure was elucidated by extensive spectroscopic methods, including IR, UV, HR-ESI-MS, and NMR techniques (1D and 2D NMR). The structure was supported by comparison with previously reported data for 8,13-dioxo-14-methoxycanadine, HMBC correlations confirming the butoxy group at the C-14 position, and other spectral data, leading to the identification of compound 1 as 8,13-dioxo-14-butoxycanadine.