Abstract: Much attention has been paid to sleep research throughout the whole world during the last ten years. Beside the formation of the Chinese and other Sleep Research Societies (SRS),the Asian Sleep Research Society (ASRS) and the World Federation of Sleep Research Societies (WFSRS)also were born during this period. The objective of this paper was to discuss some contemporary theoretical questions in sleep research as follows:the core problem of sleep is deep Slow Wave Sleep (dSWS), how sleep is controlled by the circadian rhythm,the comparative analysis between paradoxical sleep and wakefulness, the importance of rehabilitation of siesta in the world community,clinical sleep disorders and its countermeasure, as well as the endogenous sleep-inducing substances.

Key words: deep Slow Wave Sleep (dSWS), circadian rhythm, Siesta, clinical sleep research, sleep substances