Abstract: A system and a method for transmitting serial data, and a recording medium thereof are provided, in which a host is connected to a portable device through network, and the portable device is connected to a serial device. The host includes a host control module, a data convert module, and a first communication module. The host control module generates and receives serial data. The data convert module is connected between the first communication module and the host control module to convert formats of serial data and network packet data. The first communication module performs communication of network packet data between the data convert module and the portable device. The portable device is configured between the host and the serial device, and converts formats of the serial data and the network packet data by using a bridge module, so as to establish connection between the host and the serial device.