Li J, Liang J, Wang J, et al. - Given the value of information concerning the spatiotemporal trends of the maternal mortality ratio in the policymaking response to reducing the maternal mortality ratio (MMR) in developing areas, researchers conducted this study to aid the government to preassess the effects of policy by determining the corresponding magnitudes of influence of the underlying determinants. The quantitative statistical results of national and subnational influencing effects and patterns can aid the government to develop policies with precision. A Bayesian space–time model was used to determine the spatiotemporal trends of the MMR in 2,205 Chinese counties from 2010 to 2013 and Bayesian multivariable regression and GeoDetector models were employed to address 3 main ecological determinants of MMR, including per capita income (PCI), the proportion of pregnant women who delivered in hospitals (PPWDH), and the proportion of pregnant women who had at least 5 check-ups (PPWFC). Medical intervention factors are identified to be the major determinants of the MMR in China. The MMR will reduce by 1.787 and 0.623 per 100,000 live births when the proportion of hospital births and the proportion of 5 or more antenatal care visits raise by 1.0%. In the western and southwestern regions of China, the major determinants for the MMR are noted to be per capita income and antenatal care, while in the eastern and southern coastal regions, it is per capita income.