外延X射线吸收精细结构(extended X-ray-absorption fine structure,EXAFS)技术是研究局部结构和动力学的有力工具。它在探讨引起材料负热膨胀(negative thermal expansion,NTE)机理方面能提供详细信息。本文在简要介绍EXAFS后, 对EXAFS和Bragg衍射进行了比较,介绍和比较了具有不同结构的NTE晶体的最新研究结果。在有关NTE研究中,能从EXAFS获得的物理量包括:邻近键的真实膨胀和相关原子振动的各向异性。对现有的结果和仍待展开的某些问题进行了讨论。 The extended X-ray absorption fine structure (EXAFS) technique is a powerful tool to study the local structure and dynamics. It provides detailed information on the mechanisms that cause negative thermal expansion (NTE) of materials. After a brief introduction of EXAFS, this article compares the EXAFS and Bragg diffraction, and introduces and compares the latest research results of NTE crystals with different structures. In the NTE study, the physical quantities available from EXAFS include the true expansion of adjacent bonds and the anisotropy of the associated atomic vibrations. The existing results and some questions still to be explored are discussed.