A server system includes a BMC, a BIOS chip, an IPMI and a diplexer. The BMC includes a first chip-selecting signal output terminal, a second chip-selecting signal output terminal, a first updating output terminal and a controlling input terminal. The BIOS chip includes a second chip-selecting signal input terminal and an updating input terminal. The IPMI has a controlling output terminal. The diplexer includes a first input terminal and an updating output terminal. The first input terminal of the diplexer is electrically coupled to the first updating output terminal of BMC. The updating output terminal of the diplexer is electrically coupled to the updating input terminal of the BIOS chip. The controlling output terminal of the IPMI is electrically coupled to the controlling input terminal of the BMC. The second chip-selecting signal input terminal of the BIOS chip is electrically coupled to the second chip-selecting signal output terminal of the BMC.