Tropomyosin (TM), is a coiled-coil dimmer which modulates actin filament properties, has been implicated in the control of actin filament dynamics during cell migration, morphogenesis, and cytokinesis. However, the expressions and possible functions of tropomyosin in central nervous system (CNS) lesion remain unknown. In this study, we found the expression of tropomyosin gradually increased in rat brains subjected to traumatic brain injury (TBI). Double immunofluorescence staining showed tropomyosin was expressed in neurons and reactive astrocytes following TBI but not in quiescent astrocytes in normal brains. Furthermore, we detected that proliferating cell nuclear antigen (PCNA) had the co-localization with GFAP, and tropomyosin. In conclusion, this was the first description of tropomyosin expression in rat traumatic brain. Our date suggested that tropomyosin might be involved in the astrocytes proliferation following TBI.