Abstract: The design of client and server program is achieved in the system of electric bicycle rental client .Compared with the usual software for car rental,the system includes the function of speed limiting,besides the basic functions such as the user login,vehicle reservation,store check and order review are also included.In this paper,the asynchronous loading mechanism was adopted in the display of data,and the definition of interface was used by the communication between the client and the server.The second level cache was employed to avoid the problem of memory overflow when images are loading.This software runs smoothly and has higher security performance compared with the current car rental applications.

Key words: Android,Scala,GPS speed limit,Rental bicycle