According to the market demand, in order to satisfy the consumer for online listening music in their own mobile phone, and didn't spend too much traffic, a YOBO online music player was developed for using Android mobile operating system. This paper introduced the core technology, stated the design of the framework and the achieve results of the player's important module, used JAVA language、XML language and YOBO API technology, designed and realized five functional modules which included user authorized、user personal information display、my music box、my music radio and songs search, and gived part of the test results. So people can make use of mobile phone to realize online listening music, it is an effective way to break through online listening music of space constraints.