本文从对称(symmetry)这个词的原意及其含意在文学和科学中的演变,谈到雅俗共赏的图象对称性。然后从对称图象的定义谈到对称操作和对称元素以及有关的群论原理。在化学中经常遇到的对称图象是由原子按一定对称性构成的分子和晶体。最后探讨了对称性的起源和作用,并举例说明对称性制约分子和晶体性能的原理。 This article talks about the image symmetry of the elegant and vulgar tastes from the original meaning of the word symmetry and its meaning in literature and science. Then from the definition of symmetrical image, we discuss the symmetry operation and symmetry elements and the related theory of group theory. Symmetry images often encountered in chemistry are molecules and crystals made up of atoms that are symmetrical. Finally, we discuss the origin and function of symmetry and illustrate the principle of symmetry control of molecules and crystal properties.