Wooden activated carbon fibers (WACFs) were prepared from phenolated Chinese fir (Cunninghamia lanceolata) using CO2 activation; microstructure characterization, the adsorption capacity, BET-specific surface area, and pore distribution of WACFs were investigated by SEM and X-ray analysis. Results showed that WACFs have a smooth surface and round or elliptical cross-section. The (002) crystal plane diffraction peak of the WACFs was obviously heightened, also showing an apparent (100) diffraction peak. With increased activation temperature, the value of d ((002)) gradually decreased, whereas the values of the crystallite sizes L (a) and L (c) initially decreased and then increased. The L (c)/d ((002)) and g values corresponding to the degree of change in the graphitization structure increased. WACFs mainly have micropores as well as a few macro- and mesopores. The micropore diameter of WACFs has a narrow range (0.3-0.5 nm). With increased activation temperature, the single-point surface area, Brunauer-Emmett-Teller surface area, micropore area, single-point total pore volume, and micropore volume of WACFs increased, while the pore diameter decreased. At 900 A degrees C, the iodine adsorption and yield rate of WACFs were 779.22 mg/g and 51.48 %, respectively.