通过研究银河系与邻近矮星系之间的相互作用，不但可以帮助我们了解银河系及其邻近矮星系的总物质质量分布情况，更为重要的是可以勾勒出近邻宇宙暗物质质量的分布图景，从而对现今的星系宇宙学模型提供进一步的物理约束、并对相关理论及数值模拟加以完善。本项目计划利用GAIA的全天测量数据获取目前最大样本、位于银河系盘附近、隶属Magellanic Stream（MS）Leading Arm（LA）部分的年轻恒星的空间运动学多维参数，结合LAMOST巡天获取的海量恒星光谱数据，首次对LA成员星的金属元素丰度和运动学信息进行统计分析，探究LA的物质起源、解决目前相关理论模型与观测结果之间的矛盾；推测LA中恒星诞生的可能性和概率，验证LA结构的形成假说；确定LA形成的空间位置和分布，加深对MW引力势和物质分布模型的了解。该项目通过LAMOST与GAIA的充分结合，将在相关领域获得具有较高显示度的重要成果。

Exploring the interactions between the Milky Way and its neighbor dwarf galaxies, such as Large/Small Magellanic Clouds, could help us better understanding the models of the Galactic gravitational potential and distributions of total matters including baryonic and dark matters. Furthermore, such studies could provide better constrains on present Universal and galactic evolution model and simulations. In this program, we intend to study the formation and evolution of the Leading Arm (LA) of the Magellanic Stream (MS) by using kinematic data from GAIA and abundance information from LAMOST. Comparing the information statistically with the ones of Milky Way and its neighbor dwarf galaxies, we could understand the sources of the LA matter and could solve contradicts between present simulations and observation. Moreover, with calculations and statistics of ages for the large LA member sample, it is possible for us to test present hypothesis about the formation of the LA multi-branch morphology. Besides, it is first time that we will calculate and analysis distances of the LA members, in order to explore the space distribution of the LA and better understand the models of the Galactic gravitational potential and distributions of its total matters. In conclusion, this program will present some significant results in this region via combing and using data from LAMOST and GAIA.