According to the requirement of natural human-computer interaction for Ambient Intelligence (AmI), a Bluetooth- based authentication technique is provided. An authentication network combining advantages of Bluetooth ad hoc network with the Ethernet is introduced first in detail. Then we propose a Bluetooth badge for storing the user’s identification information. Finally, the authentication system based on Bluetooth badge and authentication network is introduced. It is demonstrated ex- perimentally that the Bluetooth-based authentication technique can authenticate the user automatically. According to the requirement of natural human-computer interaction for Ambient Intelligence (AmI), a Bluetooth-based authentication technique is provided. An authentication network integration advantages of Bluetooth ad hoc network with the Ethernet is introduced first in detail. Then we propose a Bluetooth The badge for storing the user’s identification information. Finally, the authentication system based on Bluetooth badge and authentication network is introduced. It is demonstrated ex-perimentally that the Bluetooth-based authentication technique can authenticate the user automatically.