Abstract: Chemical communication plays an important role in regulating animal social life.  It is helpful for them to maintain social hierarchy, indicate their reproductive states, recognize /discriminate conspecifics from one to another, kin vs. nonkin conspecifics.  It has been 50 years since the first pheromone was found in 1959 by Karlson and Lüscher.  Scientists have made a major progress in exploring new pheromones and the underlying mechanisms of chemical communication.  In this paper, we introduced both the general theories in chemical communication and some new findings in the study of pheromones identification, and also introduced chemical component analyses and identification, sensory path and perception of different pheromones, the functions and the related physiological and genetic factors affecting chemical communication.  The future trends in the study of pheromone detection and behavioral bioassay were also discussed.

Key words: Semiochemical, pheromone, odor, vomeronasal organ (VNO), social behavior