Between the present invention relates to a process for producing high molecular weight olefin in improved yield from a substantially lower molecular weight hydrocarbon feedstock in a narrow range containing the olefin in the reaction distillation column, the production method is the bottom and the top of the reaction distillation column supplying a substantially hydrocarbon feedstock with a narrow range containing the olefin to the reaction distillation column at a predetermined point, and performing an olefin in the predetermined feed point alternately to the isomerization catalyst or isomerisation catalyst and a step of contacting the mixture thereof while to and in contact with the disproportionation catalyst, while maintaining the profile of the reaction was adjusted in the distillation column at a temperature and pressure generated collecting the high molecular weight reaction products of low molecular weight reaction product, and the liquid phase of the gas phase and react with the catalyst to the olefin of the desired high molecular weight and a step of maintaining the reaction mixture to / liquid equilibrium. Catalyst, olefins, high molecular weight, hydrocarbon, groups / liquid equilibrium, the reaction distillation column, isomerization, disproportionation