Periodontal disease is common infectious diseases in oral cavity. Research has revealed that the situation of periodontal tissue related closely with systemic health recently. Much of traditional cause cannot fully explain how preterm low birth weight（PLBW） happens, 25%-30% of which are unknown etiologically. As a potential risk factor, the relationship between periodontal disease in pregnant women and the occurrence of PLBW has begun to raise concerns. This paper reviewed the relationship between periodontal disease and PLBW including the possible mechanisms．
