Abstract: This invention relates to a computer system with hot swap function, the computer system comprises a computer peripheral device having a signal connector in a predetermined position, a mother board having a Basic Input Output System (BIOS), a software controller for controlling the signal communication of the computer system and the power of the computer peripheral device, and a circuit board forming on one slot which is used for accommodating the computer peripheral device. The circuit board comprises a first connector and a second connector for connecting with the computer peripheral device, and a signal connection device for connecting with the motherboard and the software controller. The first connector and the second connector connect with the signal connection device through the circuitry of the circuit board.