Learn Chinese with @cn-reader :传宗接代
Idiom：传宗接代（chuán zōng jiē dài）
It means that give birth to a son to carry on his family name and carry on the ancestral line.
In ancient China, boy is very important and necessary for one family. Son has more rights than girls in family. They can inherit family money and social status. Each family has one same aim is that we must give birth a boy. This is duty and destination.
In fact, they are three reasons why this ancient rule happens.
Firstly, as all you know the girls will get married and move to husband’s home. Under this situation they will leave far from parents, each year they have a few chances to go back home and stay with their mother and father. Contrarily, boys can live with parents forever no matter if they are married. At last, they can take care of parents when mother and father are old.
Secondly, surname is very important in China. When girls are married, their children’s surnames are changed to follow girls’ husband surname. Besides, girls are husband’s family person. But, boys’ children are still the same surname.
Surname is the basis and vital root for a family, only boys can carry on this ancestral line.
The last reason is that boy is stronger than girl. They can protect the whole family and prop up the whole family.
But now is the new century, girls are the same as boys. Women have the equal rights as men. The idea of having to give a birth to a boy has disappeared as time passing.