作为一类年老的高光度天体，M巨星相比其他巨星能够在更远的距离被探测到，因而更适合作为示踪天体来研究银河系结构。本项目将基于郭守敬望远镜（LAMOST）海量的光谱巡天数据，从中挑选出可靠的M巨星光谱样本，这对于银河系结构和演化的统计研究将具有十分重要的科学价值。我们计划以郭守敬望远镜光谱巡天数据为基础，创建一套高信噪比的M巨星光谱模板，继而利用模板匹配方法来实现对大样本M巨星的搜寻和分类，得到目前为止最大的M巨星光谱样本（约4~5万）；同时获取M巨星的多波段测光、视向速度、自行、距离、金属丰度、光谱类型等各项重要参数，构建基于郭守敬望远镜巡天的大样本M巨星星表；并进一步应用到银河系反银心方向的统计研究中，为子结构和星流的相关研究提供关键性的数据支持。

M giants are red-giant-branch (RGB) stars with low surface temperature and high luminosity in the late-phase of stellar evolution. Its luminous nature allows us to use these stars as good tracers to study the outer Galactic halo and distant substructures. A well classified M-giant stars sample has important scientific values for the statistic research of Galactic structure and evolution. In order to fully utilize the spectral data of LAMOST spectroscopic survey, we plan to further categorized M-giant stars. In this project, we will assemble a set of M-giant spectral templates with high signal-to-noise ratio in the LAMOST data. Then, we can use the template-fit method to automatically identify and classify M-giant stars in spectra from the LAMOST regular survey. We will present a spectroscopic catalog of all M-giant stars including stellar parameters like photometry, proper motion, radial velocity, metallicity, distance, spectral type and so on. In particular, the large sample of M giants research is carried out for the first time. We will further use this sample to study the sub-structures and tidal stream in the Galactic Anti-Center.