A general, simple, eco-friendly, and scalable route of obtaining highly adsorptive activated carbon from biomass using ZnCl2 molten-salt process is reported. Upon using three biomasses (pine wood chips, banana peels, and pine leaves) as the model carbon precursors, the molten-salt process yields different porous structures of carbons with a specific surface area up to 1624.8 m(2) g(-1). The properties of the three obtained activated carbons were characterized by SEM, TEM, XRD, FT-IR, and BET. The results show that all of them are amorphous with oxygen-containing functional groups on the surface. Besides, they exhibit remarkable adsorption capacity for removal of methylene blue of 425, 225, and 300 mg g(-1), respectively. Since various biomasses can be transformed into activated carbons, molten-salt route is proved general and feasible, which offers a simple and environmentally sound way for transforming low-cost and abundant biomass to highly adsorptive and valuable activated carbon. This method also opens up a new avenue toward the application of biomass in various fields.