The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) is a special active reflecting Schmidt telescope. LAMOST adopts an innovative active optics technique that changes mirror surface continuously to achieve a series of different reflecting Schmidt systems at different moments. It breaks through the bottleneck of the large-scale spectroscopic survey observations with both large aperture (clear aperture of up to 4.9 meters in diameter) and wide field of view (5 degrees). It is a combination of the thin deformable mirror active optics and segmented active optics. Its spherical primary mirror and active aspherical correcting mirror are both segmented with 37 and 24 hexagonal sub-mirrors respectively. It is the first telescope using two large segmented mirrors in one optical system in the world. By using the distributive parallel controllable fiber positioning technique, the focal surface of 1.75m in diameter can accommodate up to 4000 optical fibers. LAMOST has 16 spectrographs with 32 CCD cameras. Therefore, it is the telescope of the highest spectrum acquiring rate in the world.
      As a national large scientific project, LAMOST project was proposed formally in 1996, and approved by Chinese Government in 1997. The construction was started in 2001 and completed in 2008. In June 2009, LAMOST passed the official acceptance organized by National Development and Reform Commission.
      How has the universe been formed and evolved? How do these billions ofgalaxies in the universe formed and evolved? How has the Milky Way, ourown galaxy, been formed and evolved? In the whole history of humancivilization, these basic and profound questions inspirit people to explorethe nature.
      Astronomical spectroscopy plays a very important role in exploring thesequestions and the optical spectra contain abundant physical information ofdistant celestial objects, and acquiring spectra of a large number of celestialobjects is desperately needed in astronomy, which touches upon variouscutting-edge researches of contemporary astronomy and astrophysics.
      The combination of large aperture, wide field of view and 4000 fibers makesLAMOST the most powerful optical spectroscopic survey instrument in theworld. Our scientific goals focus on the structureand evolution of our Galaxy, galaxies and cosmologyand multi-band identification. The Galacticspectroscopic survey will produce a spectroscopic database of millions ofstars. These data will make substantial contributions to the study of theglobal structure and substructure of the Galactic spheroid, the matterdistribution and the gravitational potential of the Galaxy, the structure ofdisk and spheroid in its anti-center, search for extremely metal poor stars,the open cluster and their relationship with structure of the Galaxy.The extragalacticspectroscopic survey will cover both north and south galactic polar caps toget spectra of galaxies and quasars, which will make contribution to the study of formation and evolution of galaxies. LAMOSTspectroscopic survey combining with the surveys in other wavebands, suchas radio, infrared, X-ray and gamma-ray will make important contributionsto the multi-waveband cross-identification of celestial objects.