PURPOSE: To produce hydrocarbon good in catalyst stability and liquid in normal state by passing a hydrocarbonaceous supply raw material containing an olefin through a reactor containing catalyst particles upwardly at a specified temp. and under a high pressure.

CONSTITUTION: A hydrocarbonaceous supply raw material containing 2-6C olefins is passed through a reactor storing catalyst particles containing a crystalline support stagnated for at least one hr under a reaction condition upwardly at a temp. from 150 to 295°C, pref., from 180 to 280°C under a high pressure to obtain objective hydrocarbon. The above mentioned catalyst pref. contains crystalline aluminosilicate (pref., ZSM-5, mordenite) and nickel.