Abstract　

 　 　 
Water is the major constituent of all living organisms. More importantly, liquid water was essential for the origin and evolution of life. In the past, water plays a unique role in shaping the early solar system. Today, studying the water distribution in the solar system, especially investigating water features in the small body populations, which have experienced less thermal evolution and less surface processing, may shed light on the outstanding questions, such as the history of planet formation and the origin of terrestrial water. In this talk, I will focus on the physical properties, particularly, the water distribution in three small body populations of the solar system: (1) the Jovian Trojans, (2) the main-belt B-type asteroids and (3) the comets.