Aim To investigate the effect of oxidized low density lipoprotein(ox-LDL) on Fractalkine expression in cultured human umbilical vein endothelial cells (HUVEC) and explore its mechanism.Methods HUVECs were isolated and cultured,the passage 2～5 cells were used in experiment.HUVEC were coincubated with different concentrations of ox-LDL (5,25,50 and 75 mg/L) for 48 h or with 50 mg/L ox-LDL for different times(6,12,24,48 and 72 h).SB203580(20 μmol/L),an inhibitor of p38MAPK activation,was pretreated for 60min before HUVEC were coincubated with 50 mg/L ox-LDL for 48 h.Fractalkine mRNA and protein expression were detected by RT-PCR or ELISA.The phosphorylation of p38MAPK was determined by Western blot.Results The expressions of fractalkine in HUVEC were upregulated by ox-LDL(5,25 and 50 mg/L) in a concentration-dependent manner and were increased by ox-LDL(50 mg/L) for 6,12,24,48 and 72 h in a time-dependent manner;Compared with control group,the phosphorylation of p38MAPK was increased significantly in ox-LDL group (P<0.05),SB203580 (20 μmol/L) decreased ox-LDL induced fractalkine expression.Conclusion ox-LDL stimulates the expression of fractalkine in a concentration and time dependent manner,p38MAPK activation may mediate ox-LDL induced fractalkine expression.