Nacre, ormother-of-pearl, a main structural material forming the innerlayer of mollusc shells, displays excellent mechanical properties.It became a hot research topic recently in biomimetic design andsynthesis for advanced engineering materials. The hierarchicalmicrostructure of this biological material is so well organizedthat its strength and toughness are far superior to the pureceramic that the material is made of. In this paper, we summarizerelevant studies on the microstructures, mechanical properties,and mechanical modeling of nacre. Problems in the study of nacreare pointed out and discussed briefly.