Abstract: A USB (Universal Serial Bus) hub with built-in storage device is comprised of an upstream interface port to be operated under the USB (universal serial bus) transmission control protocol for serving as a data-switching communication port of relevant devices; a hub device, further comprising a hub control unit, a packet-switching unit, a router, a built-in storage device, and a repeater; and a downstream interface port to be operated also under USB transmission control protocol, being provided with a plurality of interface ports to serve as a data-switching communication port of relevant devices. Therefore, the USB hub of the present invention can serve as an interface for switching connection between USB interfaces with different transmission speeds, such as USB1.1 and USB2.0, for data transmission.