The topic of having a boy or a girl has always attracted much attention, but the reliability index of various prediction methods varies. The statement that sour men and hot women are unscientific; fetal heart rate cannot accurately determine the gender of the fetus; the accuracy of B-ultrasound examination is affected by the doctor\’s skills; chorionic villus biopsy and amniocentesis, although highly accurate, are also risky; Although the blood test method is accurate, it is banned in the country. The important thing is to treat boys and girls rationally, pay attention to the health of the baby, and cherish every reincarnated little life.