Abstract: Objective To analyze the maternal mortality rate(MMR) and trends in Baoan district, Shenzhen, China from 1999 to2018. Method The individual data of maternal deaths in Baoan district in the past 20 years were collected from the original registration form and Shenzhen Maternal and Child Health Management system. The MMR, the changing trend, the characteristics and the causes of death were statistically analyzed. Result The overall MMR in Baoan district during the past 20 years was 18. 86 per100,000 live births, with a declining tendency. The MMR decreased by 96. 04%, from 82. 61(in 1999-2003) to 3. 27 per 100,000 live births(in 2016-2018). Subgroup analysis revealed that MMR was higher among migrant women(31. 57 per 100,000 live births), women aged≥35 years(47. 62 per 100,000 live births) and those who gave birth outside of the hospital(729. 26 per100,000 live births). The top three main causes of maternal death included obstetric hemorrhage(27. 69%), amniotic fluid embolism(22. 31%) and complications(15. 38%). The proportion of obstetric hemorrhage decreased from 29. 35% in 1999-2008 to 23. 68%in 2009-2018, while the proportion of amniotic fluid embolism increased from 20. 65% in 1999-2008 to 26. 32% in 2009-2018,which becoming the leading cause of maternal death in Baoan district in the past decade.Conclusion Baoan district had experienced a fast decline in MMR within last two-decade period, but still needed to emphasis on high-risk pregnancy early warning, full management and improvement of obstetric technicians' ability, so as to further reduce maternal deaths.