The shell for a mobile device comprises one or more functional modules attached to the shell and a connector, the functional module being capable of being electrically connected to the mobile device via the connector and a first interface of the mobile device, for providing a corresponding function for the mobile device. Such a shell can not only provide protection function for the mobile device but also can enhance the performance of the mobile device, enrich the function of the mobile device and promote the user's experience in using the mobile device.