Abstract: In ultra-wideband (UWB)-based indoor positioning, the number of base stations used for location calculating is always affected by non-line-of-sight (NLOS) propagation or sheltering, and thus leading to no solution of location equations. This paper proposes a precise indoor localization algorithm based on received signal strength indicator (RSSI) and UWB ranging techniques. The multiple RSSI measurements of wireless local area network (WLAN) is transformed into the corresponding distances, which can be used to improve the positioning accuracy of the UWB. Our technique can localize targets by minimizing the positioning errors with only one UWB base station. Compared with the existing least squares (LS) and maximization likelihood (ML) algorithms, our method achieves better performances in arbitrary structure of base stations with low computational complexity.