Bluetooth shares the 2.4 Ghz ISM(industrial, scientific, and medical) band with WLAN system based on the IEEE 802.11 standard, Cordless phone and microwave oven. Because they operate in the same radio band, mutual interference is serious. Especially in an office environment, Bluetooth and WLAN system will typically operate simultaneously. They create the interference between themselves and their performance is worse. To enable coexistence between Bluetooth and WLAN an adaptive frequency hopping technique for a frequency-hopped Bluetooth system has been proposed. In this paper, an interference-detection-based hopping algorithm using 3 channel states is proposed. The performance of that is evaluated and the Bluetooth is designed on the basis of platform and implemented.