Abstract: Objective To set up a classification standard of mild and moderate traumatic brain injury,for the purpose of reliable data comparison derived from different laboratories. Methods Traumatic brain injury (TBI) in rats was prepared by using a metallic pendulum-striker device. After injury, five variable parameters including the time of apnea and the areflexia, time of corneal reflex, external auditory canal stung reaction, body-righting reflex and needling reaction were determined and scored by using rat coma criterion. These data were judged and classified into mild and moderate head injury by brain patho-anatomy changes. Then the data were used to set up a multivariate discriminate equation.Results The distinguished probability of mild and moderate TBI according to actual direct measured value and the criterion were 88.9% and 91.9%, respectively. Conclusion This method is able to classify mild and moderate TBI in rats.

Key words: forensic pathology, rats, traumatic brain injury, coma, classification standard