Group B streptococci are Gram-positive cocci that play an important role in perinatal infections and can lead to a variety of adverse perinatal outcomes, including late abortion, fetal growth restriction, premature rupture of membranes, and preterm delivery. Neonatal infection with group B streptococcus can be divided into early-onset and late-onset cases. Early-onset cases are vertically transmitted from mother to child and most commonly manifest as sepsis, pneumonia, and meningitis with a high mortality rate; late-onset cases can develop through horizontal transmission or vertical transmission, which is lower than early-onset cases and can manifest as meningitis and bacteremia. Perinatal screening for group B streptococci and prophylactic antibiotics during delivery and for newborns with positive screening can significantly reduce the severity of early-onset group B streptococcal infections in newborns, but have no direct effect on late-onset group B streptococcal infections. Therefore, screening all pregnant women for perinatal group B streptococcal infections is of great importance.