Brillouin optical time domain analysis (BOTDA) is presently the mainstream in distributed optical fiber measuring techniques. Research progress and technical methods are introduced. The characteristics and the main technological limits of BOTDA are stated in this paper. Two novel techniques, pulse-prepump-BOTDA (PPP-BOTDA) and differential pulse-width pair-BOTDA (DPP-BOTDA), with which special resolution, measuring precision and signal-to-noise ratio (SNR) can be improved, are introduced. New techniques that employ the characteristics of polarization-maintaining fiber (PMF) and photonic crystal fiber (PCF) to measure temperature and strain simultaneously are introduced.