By using the infrared spectroscopy，elemental analysis and mensu-ration of specific surface ere techniques，we have investigated the earbonizing-aetivating mechanism of the hollow activated carbon fiber SNACF．Experimental results have demonstrated that the mechanism features of preparation of SNACF are remarkably distinct from those obtained from NACF．In the ease of SNACF．during the carbonization process thiocycanic aeid gas (2060--2075 cm-1 peak) and tar-like substance with —SO3H groups were released．Moreover，the released amount of gas containing N (HCN，NH3) deerea-ses while its telaese temperature is higher as compared with those of NACF．During the activating process more specific surface can be obtained，and the time of activation can be decreased．These differences are closely associated with the texture features of precusors used and thier chemical composition．