Abstract: Objective To investigate the expression of heme oxygenase-1（HO-1） at different intervals and to provide evidence for estimation on injury intervals after brain contusion in human. Methods Twenty-four patients died of serious brain injury were assigned as injury group and 4 patients died of non-brain injury were served as control group. HO-1 expression was analyzed in brain tissue at different time intervals（3 h, 6-9 h, 12-24 h, 36 h-3 d, 5-8 d, 17-20 d） by immunohistochemistry and auto-image analysis system. Results The level of HO-1 expression started to increase in 3 h after brain contusion compared to the control group（P<0.05）. The level of HO-1 expression highest level in 12-24 h group, and maintained high level in 36 h-3 d, then decreased gradually. Conclusion The expression of HO-1 might be a strong evidence for human brain contusion time estimation.

Key words: forensic pathology, brain injuries, heme oxygenase-1, immunohistochemistry, injury time