A battery case for an electric bicycle and a mounting structure thereof is disposed at the handlebar of an electric bicycle. If the battery case is provided with battery indicator, speed indicator, headlight and the like instruments, the user rider can read it easily, and the battery case also can be used as a meter. Thus, not only the meter cost is saved, but also the circuit installation is simplified. Furthermore, the battery case is loaded on the flanges of the mounting base, and the connection between the battery case and the mounting base is strengthened by a projection and a locking cavity. Therefore, the battery case not only can be easily assembled and disassembled but also can be positioned firmly.