Abstract: The aim of this study was to determine the expres-sion of heat shock protein 70 （HSP70）as molecular chap-erones ，following tratunatic brain stem injury （TBSI） Theexpression HSP70 was detected in respective brain re-gions of rats 1h, 3h, 6h, 12h, 24h after brain stem stab-bing wound. Numerous HSP70 immunoreactivity positive blood vessel endothelioid and glia cells were found in ce-rebral, cerebellar cortex and hippocampus after lh, withH. E stain unchanged. In the area near the focal of brainstem injury ，HSP70 immunoreactivity positive neurons in-creased significantly after 1h of injury, reaching the high-est level ds 3h, much higher than in other areas.HSP70 immunoreactivity positive cells still existed after24h of injury. It was suggested that TBSI cause the de-fectiveness of protein structure in brain， and induceHSP70 proteolysis of denature Protein including mistold-ing or aggregate. TBSI can be diagnosed regionally by theincreasing of HSP70 immunoreactivity positive neurons in the focal of brain stems.

Key words: heat shock proteins, traumatic brain stem injury, immunohistochemistry