OBJECTIVE To explore the relationship between the expression of EIIIA+ fibronectin in incised wound of rat's skin and injury time. METHODS The wounding model was established by cutting the dorsal skin of 48 adult SD rats. The rats were sacrificed at the pre-set injury time as immediately, 0.5 h, 1 h, 2 h, 3 h, 4 h, 6 h, and 8 h. The skin samples were taken at the margin of wound. The expression of the EIIIA? fibronectin was detected by immunohistochemistry and Western blotting and the relationship be- tween its expression and injury time was observed. Results The expression of EIIIA+ fibronectin was not observed immediately. The basal cell of skin began to show positive expression 0.5 h after injury. With the extension of injury time, positive staining became stronger. The value of relative optical density was gradually increased with prolonged injury time by the Western blotting analysis. CONCLUSION The expression of EIIIA+ fibronectin could be used for estimation of injury time in the early stage of skin injury.