Bronchopulmonary dysplasia (BPD) is a disease of very low birth weight and extremely low birth weight infants with multifactorial etiology including premature birth,ventilator induced injury,oxygen stress and inflammation.Most of the medical therapies and strategies are supportive.Steroid is the most effective medical therapy but because of its long-term adverse effect,the use of steroid should not be given routinely but should be decided based on individual consideration,in conjunction with the family.For the prevention and treatment of BPD,future research should be focus on mesenchymal stem cell implantation and local steroid administration using surfactant as vehicle.