The wireless charging system includes a base member for placing a to-be-charged device, a wireless power transmission module for wireless charging the to-be-charged device through a magnetic resonance unit, an impedance detection module, a power throttle module, an information reception module. Through the wireless charging system, firstly, the to-be-charged device is wireless charged on the base member. Secondly, when the to-be-charged device is not a desired object and reveals a higher impedance value, the impedance detection module would detects this and inhibits/throttles the wireless power transmission module. Thirdly, if the to-be-charged object is a desired one but attached with some metallic object such as a metallic back cover, the wireless charging system may continue wireless charging according to the impedance information from the wireless reception module.