The influence of the explosive blast with different pressures on the permeability of the pulmonary microvascular endothelial cells monolayer(PMECM)was observed.The results showed that the explosive blast about 100kPa might increase the permeability of PMECM.The explosive blast lower than100kPa could mainly cause the ex-panding of the gap between endothelial cells while that higher than100kPa might result in the exfoliation of cells monolayer.