In recent years, mobile software has been rapidly developing. The key requirement of mobile software is to ensure optimum power throughout its run. Unlike testing other software properties, energy testing is usually done on real devices to check actual energy consumption. As such, testers need to have optimal test data to save time and effort in testing. In this paper, we propose an approach to automatically generating test data in mobile software testing, concentrate on energy properties. The approach, firstly, builds CFGs (Control Flow Graph) from the source code of the application. We then propose algorithms to select testable paths from CFG such that the mobile applications consume more energy. Finally, test data are generated from the testable paths.