The surface chemical structures and adsorption properties of three types of plant-based carbonaceous adsorbents: coconut-shell activated carbon(CAC4),sisal stalk-based activated carbon (SSAC) and sisal-based activated carbon fiber(SACF) were investigated on the basis of the previous study on their pore structures. The surface chemical structures were characterized by XPS, and the adsorption conducted onto these carbons included: liquid-phase adsorption of phenol, iodine and methylene blue; adsorption of organic solvent vapor; and the redox adsorption of Au3+ from aqueous solution. The results show that the three carbons contain several kinds of functional groups on the surface, and SACFSSACCAC4 in adsorption capacities. The adsorption property of carbonaceous adsorbent is determined by not only the pore structure, but also the functional groups on surface.