A system or method for producing gasoline from natural gas via methanol can effectively use the heat of reaction generated during the synthesis of gasoline and is capable of readily cooling the gasoline synthesis column in the production of gasoline from natural gas via methanol. A steam reformer 10 steam-reforms natural gas to generate reformed gas, methanol is synthesized by a methanol synthesis column 20 from the reformed gas, and in synthesizing gasoline from methanol by using a gasoline synthesis column 30, combustion air 41 to be supplied to the steam reformer 10 is preheated with the heat of reaction generated in the gasoline synthesis column 30, and then the preheated combustion air 41 is supplied to the steam reformer 10.