For a better understanding of the properties of bamboo lignin and of its delignification mechanism in pulping processes, milled bamboo lignin (MBL) from sinocalamus affinis was isolated and characterized by using 1H-NMR-, UV- and IR-spectroscopy, nitrobenzene oxidation and elemental analysis. It is shown that the bamboo (Sinocalamus affinis) lignin is a GSH-type lignin. Arabinose, fucose and xylose were found in bamboo lignin and a very close assciation between lignin and polysaccharides is suggested.