自从1956年以来,宇称不守恆在物理学界已经是家喻卢晓了。在达方面有过不少解释性的文章,但达些文章多半是就宇称谈宇称,使一般读者看过后很难体会,为什么宇称不守恆具有这么重大的意义。分析起来,其所以对宇称“不守恆”的意义体会不够,原因在于对宇称守恆律的重大意义首先就理解不够。这反映出了师范学院教学工作中的一个重要问题。实际上,时空对称性是近代物理学中的一个基 Since 1956, the parity of parity has become a metaphor in the field of physics. There have been quite a few explanatory articles on the subject, but most of the articles are mostly difficult to understand after talking about the parlance of the parody so that the average reader can not see why there is such a great significance in the parlance of non-conservation. Analyzed, its understanding of the meaning of “non-conservation” of the parity is not enough because the great significance of the conservation of parity is not understood enough at first. This reflects an important issue in the teaching of normal college. In fact, space-time symmetry is a base in modern physics