追溯银河系的形成历史，理解银河系的形态、结构和性质是二十一世纪天体物理学的重大问题。化学元素丰度资料可提供银河系各个星族乃至子结构的起源和演化等重要信息，区分各自所经历的演化过程。精确化学元素丰度的获取依赖于对大量恒星的中高分辨率的光谱。LAMOST计划在未来的五年中分辨率光谱巡天中获取数百万恒星的光谱，以此为契机，我们将构建一套精确的谱线表，并以此为基础计算理论光谱作为模板，通过模板匹配的方法，确定LAMOST中分辨率光谱中15种主要常见元素的丰度，并将其提供给国内外天文学家，通过高维度的化学标签对银河系内数以百万计的恒星进行分类，进而揭示银河系整体的起源和演化。

Tracing the evolution history of our Galaxy and understanding its detailed structure is one of the outstanding questions of the modern astrophysics. The chemical abundances provide key information for the origin and evolution of every population and substructure in the Galaxy, from which one can reveal those processes that our Galaxy has went through. Reliable chemical abundances that could draw the whole picture of the Galaxy usually can be only obtained from the medium-/high-resolution spectra with a vast number of stars being observed. Taking the great opportunity from LAMOST medium-resolution survey, we will generate a set of spectra lines with calibrated line data, from which the chemical abundances of 15 elements can be obtained by matching the theoretical spectral templates with the observed medium-resolution spectra from LAMOST. Driven by those data, stars can be assigned into different groups with various origins or evolution histories through the analysis to millions of the spectra in a high-dimensional chemical tagging space, which will provide strong constrains for our Galaxy evolution history.