The present invention provides a method for supplying fuel to a fuel cell, in which a monitoring period is determined for monitoring the fuel cell, and then a feeding amount of fuel is determined by integrating characteristic value generated from the fuel cell in the monitoring period. In another embodiment, it is further comprising a step of determining the variation profile associated with the characteristic value during the period so as to judge whether it is necessary to feed the fuel into the fuel cell or not. By means of the present invention, the supplying of fuel to the fuel cell under dynamic loadings can be effectively controlled for optimizing the performance of the fuel cell as well as reducing the cost without installing any fuel sensor.