A bidirectional radiooverfiber system using a single light source was demonstrated. A tunable laser was simply configured to produce the constant frequency laser source at central station(CS), and the baseband signal was modulated in optical carrier through integrated optical modulation technology(frequency modulation, intensity modulation), eventually forming a 60 GHz millimeterwave downlink signal. And, the same optical carrier was reused at base station for uplink connection. The system combined the characteristics of optical carrier reuse technology and integrated optical modulation technology, so as to use resources reasonably and simplify the base station structure. Simulation result shows that the bidirectional 2.5Gbit/s data is successfully transmitted over 20 km singlemode fiber for both upstream and downstream channels with less than 0.5dB power penalty. Relative to the existing technical scheme, the transmission system has advantages in the transmission power, the transmission distance and transmission performance.