Abstract: An expansion station for a personal digital assistant includes a keyboard module, an internal circuit, an interface port unit, a cover module, and an I/O connector. The internal circuit is mounted in the keyboard module and is connected electrically to a keypad unit of the keyboard module. The interface port unit is mounted on the keyboard module and is connected electrically to the internal circuit. A positioning space is configured in an inner surface of the cover module for positioning removably the personal digital assistant therein. The I/O connector is disposed in the positioning space and is adapted to engage an I/O port of the personal digital assistant so that electrical connection between the personal digital assistant and the interface port unit is established via the I/O connector and the internal circuit.