An electronic device and a power supplying method thereof are provided. An electronic device includes a host and a power supply. The host receives a power via a power supply path. The power is transmitted to the host via the power supply path. The power supply detects state changes of a plurality of supply current values at the power supply path obtained by the host from the power supply at a plurality of time intervals, so as to generate a determining result. A voltage value of the power is changed according to the determining result.