Conventional amphoteric and porous materials are often synthetic and polymer based; this tends to raise environmental concerns because of their poor biodegradability. To address this issue, novel natural-polymer-or amphoteric-modified cellulose and MOt (ACeOMt) composite beads with a typical mesoporous structure were developed in this study. These green-based porous beads, consisting of regenerated bagasse cellulose and oxalic acid modified montmorillonite (OMt), were successfully prepared by a facile coagulation method with fine calcium carbonate as a pore-forming agent. The beads with the best sphericity were obtained at a 1:1 weight ratio of cellulose to OMt. Scanning electron microscopy observation showed that ACeOMt possessed a smooth surface with abundant macropores. X-ray diffraction and thermogravimetric analysis characterizations demonstrated the success of the modification of montmorillonite and cellulose. The results of Brunauer-Emmett-Teller analysis indicate the presence of a typical mesoporous structure in the composite with a relatively high specific surface area. The resulting ACeOMt are expected to be biodegradable, nonhazardous, and applicable for various uses, including adsorption, chromatography, and soil remediation.