Abstract: Objective To understand the characteristics of pregnant women and the trend of birth population in Haidian District before and after the implementation of the comprehensive two child policy, and to analyze the challenges faced by maternal health care,so as to provide the basis for the government to formulate relevant policies. Methods From January 1, 2015 to December 31, 2019,the pregnant women and live births registered residence in Haidian District, Beijing were enrolled in the research. Descriptive analysis was made on the number of live births, elderly parturients, parturients, adverse pregnancy outcomes and so on. The trend χ² test was used to test the trend of the change with time. Results The number of live births in Haidian District of Beijing reached the highest value in 2016, which was 28 225 cases, and then decreased year by year, and dropped to 19 285 cases in 2019; the proportion of multipara was the highest in 2017, which was 45. 90%, and then decreased year by year, which was 36. 91% in 2019, far higher than 25. 13% in 2015. The proportion of elderly pregnant women increased gradually from 18. 88% in 2015 to 31. 31% in 2018, and decreased slightly in 2019, showing an overall upward trend(P< 0. 05);the low birth weight infants, early delivery infants, cesarean section rate showed an upward trend(P< 0. 05). Conclusion The implementation of the comprehensive two child policy has positive significance for the balanced development of population in Haidian District. However, due to the increase in the proportion of elderly pregnant women, the management of maternal health care is still facing great challenges. It is suggested that married women of childbearing age should make family planning as soon as possible and strive to complete childbearing at the best childbearing age.