Abstract: This paper analyses the obstetrical records of the Obstetrical Department of Beijing Fuxing Hospital, dealing with menarchal age, parturition age of women in Beijing area, and the body weight of their neonates. Several statistical methods have been used to find out any relation between the data of the neonates and their mothers as well as other birth background factors.
The results show that there is no notable relation between the mother's age and the weight of neonate. But the stature and weight of the mother significantly effect the weight of neonates, so does the baby's sex. The rime of the pregnancy also has something to do with neonates, weight. But it is difficult to tell how and why it does so.
Deviation analysis points out that the parturition seasons have effect on the increase of mother’s weight after giving birth. For this, no author reported before.

Key words: Neonates' weight