Abstract: Circadian clock generates endogenous rhythms to confer the fitness advantages for most organisms. Plants with the evolved self-sustaining rhythms could anticipate the changes of environment, synchronize own growth and development with oscillated outer signals. This review summarizes the emerging of research work on the various circadian rhythms, introduces the concepts of chronobiology and related theory, etc, and describes in detail on the current basic network architecture of circadian systems of higher plants, including the prominent transcriptional and posttranslational mechanism.

Key words: biological clock, circadian rhythm, chronobiology, plant