Abstract: Selective surface dissolution (SSD) method was utilized to partially dissolve the surfaces of cellulose fibers and consolidate into porous structure. After carbonization under Ar, a highly porous carbon by SSD (HPC-SSD) material was obtained, which exhibits high specific surface area (SSA) and 3D porous structure. Through SEM, BET, FTIR, XRD and electrochemical tests, the effects of two different activation pretreatment methods on the morphology, chemical composition, SSA and capacitive performance of HPC-SSD material were systematically studied. As compared with HPC carbonized directly from cellulose fibers, HPC-SSD material exhibits more stable pore-forming process, which facilitates to create a large number of micropores. The specific capacitance of HPC-SSD material pretreated by H₂O→acetone→N, N-dimethylacetamide is as high as 226 F·g^-1 (in a two-electrode configuation), which is 4.5 times that of HPC, and 40% higher than that of HPC-SSD material without any activation pretreatment.