For advocating care in normal birth and reducing unnecessary intervention in childbirth called by the WHO, we explored the comprehensive cooperation in the WHO Ⅺ project which loaned by world bank according to its activity supporting time. Many measures and practices were simultaneously performed to reduce the number of cesarean section. The results showed that cesarean delivery rate of 60.91% in 2009 before the implementation of project reduced to 37.46% in 2013, and the effect is obvious and statistically significant (P <0.05). In addition, some related medical resources, social factors, knowledge propaganda and so on, are also the reasons why cesarean delivery rate decreased.