The selectin family adhesion molecules exert a crucial role in accumulation of leukocytes at the site of inflammation. To test the biological effects of soluble selectin on lung inflammation, we introduced an expression plasmid vector of soluble selectin gene via HVJ-liposome into a murine model of LPS-induced lung injury. The myeloperoxidase activity in LPS-injected mice was suppressed by the in vivo injection of soluble P-selectin gene relative to control mice. On the contrary, soluble E- or L-selectin genes did not exert suppressive effects. Our observations suggest that P-selectin plays a crucial role in the initial steps of lung inflammation, and exogenous introduction of soluble P-selectin by in vivo gene transfer method may be a useful strategy for regulating inflammation of the lung.