The possibility that a family history of asthma may have a role in susceptibility to bronchopulmonary dysplasia (BPD) had been raised in several reports, and there was evidence of a strong association between transporter associated with antigen processing (TAP1) polymorphism and asthma in Taiwanese population. To test whether TAP polymorphism has a role in the BPD, we investigated the association between TAP1 polymorphism and BPD by analyzing the results of genotype distribution. The study included 224 ventilated preterm infants (<30 weeks) who had respiratory distress syndrome (RDS) and needed intermittent mandatory ventilation (IMV) during Jan. 1999 to July 2003. The typing of TAP1 polymorphism was performed by polymerase chain reaction (PCR)-based restriction analysis. The demography between two groups of these ventilated preterm infants was not different. We observed no significant differences in genotype distribution or allele frequency of the TAPI polymorphisms between BPD and their respective control infants. There was also no significant difference in genotype distribution of the TAP1 polymorphism with duration of IMV. Therefor, we conclude that TAP1 polymorphism is not a useful marker for predicting the susceptibility or severity to BPD for Taiwanese.