Distributed optical fiber sensors (DFOS) have attracted great research interests and successfully commercialized over the last two decades.DFOS are used widely for measurement of temperature, strain and disturbance, based on the Raman, Brillouin, and Rayleigh backscattering effects, respectively.Among them, Brillouin optical time-domain analysis (BOTDA) and Phase-sensitive optical time domain reflectometer (Φ-OTDR) have the ability of extending the sensing distance up to >150km, hence they have great potential to be applied to long-distance sensing for safety monitoring of oil/gas pipelines, electrical power lines, etc.In this paper, recent progress in DFOS at University of Electronic Science & Technology of China (UESTC) is reviewed systematically.A BOTDA and Φ-OTDR with sensing distances of 154 km and 175kin are achieved, respectively,which are the longest BOTDA and Φ-OTDR reported to date.Novel optical amplification techniques based on ultra-long fiber lasers are proposed and demonstrated to achieve these goals, and the related field trials are also demonstrated.