To follow up maintenance and check of a vehicle effectively by connecting a user terminal and a server of a vehicle information managing company via the Internet and organizing a system for giving and receiving vehicle data of a user vehicle mutually.

This vehicle information managing system includes the vehicle information managing company for managing the vehicle information of a user A, an electronic control unit 17 mounted on a vehicle 15 of the user A, a data fetching means 18 connected to the electronic control unit 17, the user terminal 16 for transmitting the vehicle data stored in the data fetching means 18 through the Internet 14, and the server 26 for receiving the vehicle data transmitted from the user terminal 16, and further includes a vehicle diagnosing means for deciding whether there is a defective part in the user vehicle 15 or not, and transmits a diagnosis result by the vehicle diagnosing means from the server 26 to the user terminal 16.