Abstract: Activated carbon (AC) was prepared from Xanthoceras sorbifolia Bunge(XSB) hull with phosphoric acid by one-step activation. The effects of processing condition on adsorption capacity of the derived activated carbons were investigated. Microporous structure, pore size distribution and glycerin decolorization effect of the optimal sample were also analyzed. The results show that activated carbon from XSB hull can be prepared at the impregnated ratio 1.5:1, temperature 600℃,time 60 min. The prepared XSB-hull activated carbon has the characters of methylene blue value 210 mg/g, iodine value 951 mg/g and pore size distribution within 2-8 nm. As an important by-product of bio-diesel, crude glycerin has some yellow color and peculiar smell which can be cleaned by adding this activated carbon of 1.5% weight of glycerin mass in 90℃ water bath to obtain an odorless, colourless refined glycerin with light transmittance of 98.5%.