Novel solid acid catalysts have been prepared from Fudan University (FDU)-type mesoporous polymers with the Ia (3) over bard and P6mm mesostructures through a carefully controlled sulfonation procedure. Various techniques have been adopted to characterize throughout their structures, porosity, acidity as well as the information related to the sulfonic acid groups. The sulfonic acid group-functionalized mesopolymers prove to be efficient heterogeneous catalysts in the reactions such as liquid-phase Beckmann rearrangement of cyclohexanone oxime and condensation of ethylene glycol with the aldehydes having different molecular sizes.