Abstract: The photoperiod is an important factor in regulating flowering time. In soybean, photoperiod regulation of flowering is one of the important factors affecting maturity and yields, and thus has attracted attentions of many agronomists. Soybeans have a wide adaptability, which is inseparable from the adaptability of different soybean cultivars to different photoperiods. The adaptation
of soybean to the photoperiod is controlled by a series of maturity genes. Under long days, soybeans need to reduce sensitivity to
photoperiod. Whereas, under short days, soybeans need to flower late to get high yields. In recent years, many maturity genes have been identified through forward genetics. Scientists have further analyzed the functions of these genes through genetics, molecular biology and biochemistry technology to get a clue of how the photoperiod regulate soybean flowering. This article summarizes the molecular identification of maturity genes and how they regulate flowering time under both long-day and short-day conditions.