Abstract: Quasicrytals discovered during 1980s are new materials.They have lots of potential applications.The experimental discovery led to exploration of an entirely new area of physics,material science as well as mathematics,and resulted in a revolution in the understanding of solid,especially in the understanding of crystal.The historical process on the discovery of quasicrytal is described,and the impact of the discovery on the study of solid is revealed.Professor Dan Shechtman,a material scientist who made the discovery,is also introduced.

Key words: quasicrystal, rotational symmetry, history of physics