Abstract: To study the effects foot and mouth diseases virus 146S particle antigen (FMDV 146S) on IL-6 release of sucking rat myocardial microvascular endothelial cells (RMMVECs) in vitro, and to provide data for solving the problem of side effects in using foot-and-mouth-disease vaccines. The cultured RMMVECs in vitro were identified as endothelial cells by morphology and by positive immunocytochemistry for factor Ⅷ-related antigen, a marker for endothelial cells. Using enzyme linked immunosorbent assay (ELISA) to detect the level of IL-6 produced by RMMVECs stimulated with FMDV 146S in cell supernatant liquid. On normal condition, RMMVECs can secrete IL-6 at low level. The level of IL-6 produced by RMMVECs stimulated with FMDV146S in cell supernatant liquid was increased dramatically in dose and time dependents, and got the maximum at 24 h. MVECs are very significant in immune and inflammatory reaction induced by FMDV 146S.