A mobile information system of a transportation tool is a mobile information system that can be connected to the Internet and can form a local area network inside. Including: a network server, used to connect to the external network and manage and coordinate the internal local area network, including: a first processing unit, a wireless Internet access module, a dial-up module, a first Ethernet interface, and a network management unit ; At least one host, connected to the network server, through the management and coordination of the network server, can be connected to the external network and form an internal local area network, including a second processing unit, a storage unit, and a memory card slot , a second Ethernet interface, an audio interface, a video interface, and an input / output interface. It can also be used with various application software inside the host according to the user's personalized use settings of the memory card, and can enjoy personal authority services on the network.