Polarization mode dispersion (PMD) is one of the important issues which limit the high-speed long-haul communication of optical fiber. It is a challenging task to recover the distortions induced by PMD for the reason of its statistical characteristics. The concepts and mathematical description, which are important to understanding of PMD are proposed. The present development of optical and electrical techniques of mitigation and compensation for PMD are presented, as well as the latest progress for PMD treatment in the world. The configurations of the optical PMD compensator, the extraction of the feedback signals and the particle swarm optimization as an effective adaptive control algorithm are described in detail.