The gas phase catalytic reaction of ethanol to butadiene, which involves dehydration and dehydrogenation of ethanol, was investigated over various catalysts in a tubular reactor. The catalysts used in the reaction were prepared by impregnation and comixing method. In a fixed bed reactor the optimum reaction conditions were sought by the response surface method. The main response was process yield and main variables were temperature of catalyst bed, flow rate of feed and amount of loading of metal oxides on supports. The liquid and gas products were analyzed quantitatively by a gas chromatograph. In a series of experiments, optimum catalyst and optimum reaction condition were found as follows : $MgO-SiO_2$ Catalyst. Metal oxide loading ; 48.84\% $MgO$ Reaction temperature; $455\,^\circ\!C$ Feed rate (W/F) ; 1.39 Kg Cat$\cdot$hr/Kg EtOH Process yield ; 22.7\% $Cr_2O_3-MgO-SiO_2$ Catalyst. Metal oxide loading ; 4.24\% $Cr_2O_3$ Reaction temperature; $450\,^\circ\!C$ Feed rate (W/F) ; 1.916 Kg Cat$\cdot$Hr/Kg EtOH Process yield ; 27.4\%