The process and function of sleep is analyzed and the occurring mechanism of sleep and the cause of insomnia are summarized in this paper.The psychics meaning of sleep and dream is explained.

• 摘要本文分析了睡眠的过程、作用，总结了睡眠的发生机理和失眠的原因，阐述了睡眠和梦的心理学意义。