An improved system and method for feeding fuel, which obviates the shortcomings of the fuel feeding system in the prior art, in which mixed fuel consisting of fine particles of solid fuel such as pulverized coal or the like and fuel oil, is directly sent under a pressure by means of a high-pressure pump but seizure of a pump plunger is caused, and which enables the fuel feeding system in the prior art to achieve good operations, are disclosed. A predetermined amount of fuel oil containing fine particles of solid fuel is fed into an oil reservoir (12) within an injection valve (9) through a control valve (16), and this fuel oil is injected through a nozzle hole (10) of the injection valve (9) with the aid of oil pressurized by means of a high-pressure pump (3). Thereby, only the above-mentioned fuel oil is injected, but the above-described pressurized oil is not injected, and also it never occurs that the aforementioned fuel oil enters the high-pressure pump (3), resulting in seizure of a plunger of the pump. The oil fed to the oil reservoir (12) is returned to an oil tank (1) via a circulation valve (21), and so, deterioration of the oil can be precluded. In addition, since the control valve (16) is regulated by a signal indicating a position of a control rack which controls a delivery amount of the high-pressure pump (3), fuel oil of the amount corresponding to the delivery amount of the high-pressure pump (3) is sent to the aforementioned oil reservoir (12), and so, only the above-mentioned fuel oil can be reliably injected.