On the relation between Cosmic Masers and Massive Star-Forming Regions

MASER (Microwave Amplification by Stimulated Emission of Radiation) emission from cosmic molecules is believed to play a vital role in understanding the early evolutionary stages of the massive star formation. Their residence in the dusty molecular envelope enables us to study the kinematics, physical conditions of different morphology and line-of-sight magnetic field toward the proto-stellar objects. A brief introduction to the history of cosmic maser discovery and its general properties is given. The recent observational and theoretical advances of interstellar MASER as well as the proposed chronology scheme in massive star forming regions are reviewed.