Abstract: According to Whitman, on passing mixed furfural vapor and steam onto Cr-Zn-Mn oxide catalyst, furan is obtained in good yield. The present authors studied certain factors involved in the preparation of this type of catalyst aswell as some of the operating conditions affecting the yield of furan.It has been found that when keeping the reaction temperature at 415℃ and concentration of furfural around 8.5 mole per cent, the yield of furan increases to a maximum as the space velocity is increased to the order of 980. Alternatively, when the space velocity and temperature are kept constant, the yield of furan goes up as the concentration of furfural is decreased. On the other hand, if space velocity and concentration are constant, the decarbonyla-tion takes place most smoothly at 415℃. When the ZnO-0.53Cr203-0.25MnO2 catalyst is prepared by precipitation at 60℃ and calcined at 550℃, a furan yield as high as 86.7% is obtained on passing the raw material at 130℃ without the use of porcelain filler. The space velocity in this experiment is 980, the reaction temperature 415℃,the concentration of the mixture 8.5 mole per cent (near the azeotropic mixture of furural-water system).