Co/Y-zeolite catalysts were prepared by three different preparation methods of excess-water(EW), ion-exchange(IE) and carbonyl complex-impregnation(CI), and they were deposited by carbon through the disproportionation of carbon monoxide at different temperatures. CO hydrogenation was performed on the fresh and carbon deposited Co/Y-zeolite catalysts respectively, and the results were compared with each other, CO hydrogenation was carried out in a differential reactor operating at atmospheric pressure, temperature of 270-400℃ and H₂/CO ratio of 2. Temperature programmed surface reaction(TPSR) of carbon deposits was performed in a thermogravimetric flow system to obtain a better understanding of the carbon deposits. The large cobalt metals existing mainly at the exterior surface of zeolite crystals in the EW catalyst had a great affinity to carbon deposits, but the small cobalt metals in the IE and CI ones were highly resistant to carbon deposits. The hydrocarbon product distributions were hardly affected by carbon deposits, while the production of olefinic hydrocarbons was enhanced significantly.