Abstract: A system for burning a liquefied gas comprises a burner gun for spraying the liquefied gas into a combustion space, a pump for feeding the gas under pressure, pipe means connecting the burner gun with the pump, and a flow regulating valve provided in the pipe means, wherein the portion of the pipe means downstream from the valve has its inner diameter so determined in relation with the flow rate of the gas that the state of the gas flow through said portion falls within fog flow zone or bubble flow zone on Baker's two-phase flow diagram.In the system of the invention, unstable combustion of the liquefied gas due to vapor lock in the pipe means can be prevented even when the gas supply pressure is below the vapor pressure of the gas. Besides, the calorific value obtained with the system is variable over a wider range than with a conventional system. Thus the system has a remarkable industrial value.