Abstract: With the maturity of the technology of caesarean section，the application of the antibacterials and the improvement of the ability of anesthesia and monitoring，the safety of caesarean section has greatly improved. The caesarean section has played a positive role in solving pregnancy complications and reducing the child and maternal mortality. But on the other hand，the high rate of caesarean section has brought the hidden troubles，increased the risks of adverse pregnancy outcomes，which also has become the problem that the whole world should face together,especially in China. In reaction to the phenomenon，this paper analyses the status of caesarean section at home and abroad，summarizes the effect factors，and points out the primary causes which lead to increase the rate of caesarean section are not only the medical factor but also the social factor. The latter has played the increasingly important role in the high rate of caesarean section. Only by the joint efforts of medical staff and society can reduce the rate of caesarean section effectively，guarantee health and safe of the mother and infant.

Key words: Cesarean section, Pregnancy complications, Infant mortality, Sociology, medical