From the perspective of resident women aged 15-49，this article interprets the future demographic trends in Beijing，and describe their characteristics with multi-dimensional demographic variables to reveal the future trend of Beijing’s population. The main findings are as follows：the size of resident women aged 15-49 in Beijing has shown a decreasing trend in the past ten years，and will decrease further in the future；the age structure of women aged 15-49 continues to age，with its peak of proportion to higher age groups；The age of marriage and childbearing of women aged 15-49 is generally delayed，marital instability is increasing，and the proportion of the first child births is decreasing；by 2035，the number of childbearing age women in Beijing will be further reduced，and the age structure will become more aging.