In recent years, many efforts have been made to form fully connected scatternet. Every point-to-point link is kept active periodically to assure the connectivity of the whole scatternet, despite of most links being fed with no traffic most of the time. In this paper, we assume that all bluetooth devices are in communication range and propose a novel method to form a temporary point-to-point piconet only when two nodes want to communicate with each other. After the communication is finished, the point-to-point piconet will be destroyed immediately. Our On-Demand Point-to-Point Piconet Formation scheme (ODP2P) resolves the defects of traditional scatternet formation in communication range. In order to reduce the communication delay, every node owns its list to record the information of all nodes. An on-event method maintains the list. The simulations show that our method can reduce the routing path significantly and provide better channel utilization for Bluetooth personal area network.