With the fast development of mobile computing terminals and wireless network, mobile learning (ML) is becoming one of the most popular research and development areas in today's e-learning. Through convenient and flexible mobile terminals and network, researchers and developers strive to provide users with teaching and learning resources and services that can be accessible anytime anywhere. This paper describes the design and implementation of a mobile learning system that can deliver live broadcast of realtime classroom teaching to online students with mobile devices. The system allows students to customize their ways of receiving, based on when and where they are tuning into the broadcast. To increase interactivity between the instructor and online students in large classes, the system also supports short text-messaging and instant polls. Through these venues, students can ask questions and make suggestions in real time, and the instructor can address them immediately