Abstract: Gas-solid chromatography (invers gas chromatography) was used to study the surfaces of copolymsr-electrodeposited and untreated carbon fibers.By adopting a series of n-alkanes and "polar" liquids as molecular probes,the retention volnmes on the surfaes of carbon fiber samples were measured under the case of "zero coverage".From the dependence of elution retention on the temperature as well as the vapor pressure of the adsorbates the, difference of the surface charaeteristic between deposition trcated and untreated carbon fidcrs was revealdd.It is shown that the enthalpy and entropy increment rsulted by aasorpting per-CH₂-segment of nalkanes on the copolymer-depesited surface is much higher than on the untreated one.Besides,the tredated carbon fiber displays strong interaction with clectron-donor prolas,on the contrary,the untreated surface has no affinity for all of the used probds.