Objective To investigate the effects of polysaccharide sulfate(PSS)on lipopolysaccharide(LPS)-induced mice pulmonary microvascular endothelial cell(PMVEC) injury in vitro .Methods PMVEC were divided into the blank control group (C) ,LPS stimulation group (L) and PSS+ LPS group (LP) .The effect of PSS on the viability of LPS-induced PMVEC was ob-served by MTT assay .The influence of polymorphonuclear(PMN) on the PMVEC adhesion number was measured by the rose Ben-gal staining .The concentrations of TNF-αand ICAM-1 in culture supernatant of PMVEC were detected by ELISA assay .Results PSS could inhibit the decrease of PMVEC viability caused by LPS(P=0 .001) ,compared with the group C ,the adhesion number of PMVEC and PMN in the group L was significantly increased(P=0 .000) ,the expression of TNF-αand ICAM-1 was significantly increased(P=0 .000);compared with the group L ,PSS pretreatment for 1 h could significantly decrease the LPS caused adhesion of PMVEC and PMN(P=0 .000) ,the expression of TNF-αand ICAM in the group LP was significantly decreased (P<0 .05) .Con-clusion PSS can inhibit LPS-induced PMVEC injury and adhesion of PMVEC and PMN ,its mechanism may be related with the de-crease of ICAM-1 and TNF-αexpression .