The recent progress in long range sensor based on Brillouin scattering has been summarized, the limitation on sensing length, spatial resolution, different approaches to improve the limitation have been discussed. Two examples on frequency division multiplexing (FDM) and time-division-multiplexing (TDM) to extend the sensing range of the distributed Brillouin sensor via BOTDA without inline amplifiers have been proposed and demonstrated. Using FDM concept we demonstrate a 75 km BOTDA with three types of 25 km fiber achieving a spatial resolution of 1.1 m and an accuracy of 1°C/20με at the end of 75 km, and a spatial resolution of 0.5 m and an accuracy of 0.7°C/14με at the end of 50 km. Using TDM technique, we demonstrate a 100 km sensing fiber of 0.6 m and 2 m spatial resolution at the end of 75 km, and at 100 km achieving a Brillouin frequency shift accuracy of 1.5 MHz, this is equivalent to 1.5°C temperature resolution and strain resolution of 30με, respectively.© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.