The influence of the explosive blast with different pressure on the permeability of the pulmonary microvascular endothelial cells monolayer (PMECM) has been observed by using the model of the explosive blast wounded the endothelial cells monolayer in vitro The mechanism of the effect of the blast on PMECM permeability has also been explored in pathology and cytoskeleton. The results show that the explosive blast with about 100 kPa pressure can increase the permeability of PMECM in conductance detection, and the explosive blast with lower than 350 kPa pressure can mainly cause the increasing of the gap between endothelial cells, and explosive blast with higher than 600 kPa pressure can exfoliate the endothelial cells monolayer. The occurrence mechanism of PMECM permeability changes caused by explosive blast is related to the change of the cytoskeleton myosin.