A fuel cell power generation system for performing power generation using hydrogen-containing gas generated from a raw material containing a hydrocarbon component and an odorizer component, the fuel cell power generation system comprising: a raw material supply section configured to control a flow rate of the raw material; a water supply section configured to supply water; an adsorptive removal section configured to cause the raw material to pass therethrough and to adsorb the odorizer component contained in the raw material; a reformer configured to generate the hydrogen-containing gas by a reforming reaction of the raw material which has passed the adsorptive removal section and water supplied from the water supply section; a fuel cell configured to perform power generation using the hydrogen-containing gas as a fuel; an accumulated flow volume measuring section configured to measure an accumulated flow volume of the raw material; and an operating control section configured to, as the accumulated flow volume of the raw material, measured by the accumulated flow volume measuring section, supplied to the adsorptive removal section from the raw material supply section increases, decrease the flow rate of the raw material to be supplied to the adsorptive removal section from the raw material supply section, characterized in that the operating control section is configured to: set a preset flow rate (f) with respect to an amount of power to be generated by the fuel cell, determine a ratio (x) of the amount by which the flow rate is to be decreased from the preset flow rate (f) based on the measured accumulated flow volume, and decrease the flow rate according to the determined ratio. a raw material supply section configured to control a flow rate of the raw material; a water supply section configured to supply water; an adsorptive removal section configured to cause the raw material to pass therethrough and to adsorb the odorizer component contained in the raw material; a reformer configured to generate the hydrogen-containing gas by a reforming reaction of the raw material which has passed the adsorptive removal section and water supplied from the water supply section; a fuel cell configured to perform power generation using the hydrogen-containing gas as a fuel; an accumulated flow volume measuring section configured to measure an accumulated flow volume of the raw material; and an operating control section configured to, as the accumulated flow volume of the raw material, measured by the accumulated flow volume measuring section, supplied to the adsorptive removal section from the raw material supply section increases, decrease the flow rate of the raw material to be supplied to the adsorptive removal section from the raw material supply section, characterized in that the operating control section is configured to: set a preset flow rate (f) with respect to an amount of power to be generated by the fuel cell, determine a ratio (x) of the amount by which the flow rate is to be decreased from the preset flow rate (f) based on the measured accumulated flow volume, and decrease the flow rate according to the determined ratio. set a preset flow rate (f) with respect to an amount of power to be generated by the fuel cell, determine a ratio (x) of the amount by which the flow rate is to be decreased from the preset flow rate (f) based on the measured accumulated flow volume, and decrease the flow rate according to the determined ratio.