Abstract: The influence of chemical modification on the structure of bamboo- shoot dietary fiber was studied by infrared spectrum and scanning electron microscopy characterization, and then the physicochemical properties of modified dietary fiber was analyzed. The results indicated that by IR spectra comparison, in 1417.08, 1331.91, 1242.02, 1143.35, 1099.67cm- 1appeared ether linkage absorption peak, so that bamboo- shoot dietary fiber had been carboxymethylated.The scanning electron microscopy indicated that modified bamboo- shoot surface was rough, had obvious cracks and gully, description of the surface structure and integrity were destroyed. Modified bamboo- shoot dietary fiber had a better expansibility, water- holding power, water combing power, content of SDF, which were higher than bamboo- shoot dietary fiber, but the cation exchange force of modified bambooshoot dietary fiber was lower than bamboo- shoot.So that chemical modification had a good improvement to the physicochemical properties and quality of bamboo-shoot dietary fiber.