A mother board adapted to rapidly charge a handheld multimedia device including a controller, a rapid charging initiation unit, a connection port coupled to the handheld multimedia device, and a switching unit. The rapid charging initiation unit provides a first voltage ranging from 3.2 V to 11 V and a second voltage ranging from 2.7 V to 0.6 V. A voltage difference between the first voltage and the second voltage ranges from 0.5 V to 0.8 V. The switching unit is coupled to the controller, the rapid charging initiation unit, and the connection port for determining whether the connection port is coupled to the controller or the rapid charging initiation unit. When the connection port is coupled to the rapid charging initiation unit, the first and the second voltage are sent to the handheld multimedia device through the connection port for activating a rapid charging function.