Polycyclic aromatic hydrocarbons (PAH) are a group of toxic pollutants existing in the environment widely, and can be taken into the body through various ways containing the digestive tract, respiratory tract and so on. Pregnant women and newborn infants are important and susceptive populations. Relevant study evidences indicate that exposure to PAH during pregnancy may be a important risk factor of preterm delivery, but the special mechanism isn't very clear and may be related with DNA damage, oxidative stress, systemic inflammation, endocrine disruption and so on. This paper reviewed related contents including the influences and evaluation methods of exposure to PAH during pregnancy, increasing risk and potential mechanism for preterm delivery of exposure to PAH during pregnancy.