AIM: To investigate the effects of hyperoside on traumatic brain injury (TBI) rats by regulating the Ras homolog gene family, member A (RhoA)/Rho-associated coiled coil-forming kinase (ROCK) signal pathway. METHODS: The TBI rat model was established by modified Feeney free fall hit method, and was randomly divided into model group, low-dose hyperoside (60 mg/kg) group, high-dose hyperoside (120 mg/kg) group, high-dose hyperoside (120 mg/kg)+ no load group, and high-dose hyperoside (120 mg/kg) + RhoA overexpression group, with 10 rats in each group, another 10 healthy rats were set as sham operation group, after hyperoside and plasmid were grouped, the nerve injury was detected by modified neurological deficit score (mNSS) and dark avoidance test; Evans blue (EB) quantitative method was used to detect the permeability of blood brain barrier in rats; ultrastructural damage of blood-brain barrier was observed by transmission electron microscopy; the levels of tumor necrosis factor-α(TNF-α), interleukin-8 (IL-8), superoxide dismutase (SOD) and malondialdehyde (MDA) in serum and brain tissue  of rats were measured with the kit; and the expression of RhoA/ROCK pathway related proteins in rat brain was detected by Western blot. RESULTS: Compared with the sham operation group, the blood brain barrier structure of the model group rats was damaged, the step-through latency and SOD level decreased obviously (P<0.05), the mNSS score, the number of mistakes, the content of EB in brain tissue, the levels of TNF-α,IL-8, MDA in serum and brain tissue, and the expression of RhoA, ROCK1, ROCK2 proteins in brain tissue increased obviously (P<0.05). Compared with the model group, the damage of blood brain barrier structure of rats in the low-dose hyperoside group and the high-dose hyperoside group was alleviated, the step-through latency and SOD level increased (P<0.05), the mNSS score,the number of mistakes, the content of EB in brain tissue, the levels of TNF-α, IL-8, MDA in serum and brain tissue, and the expression of RhoA, ROCK1, ROCK2 proteins in brain tissue all decreased (P<0.05); high-dose hyperoside group has stronger effect. Overexpression of RhoA can reverse the effects of high-dose hyperoside on various indexes of TBI rats; there was no obvious change in all indexes in high-dose hyperoside+empty load group (P>0.05). CONCLUSION: Hyperoside can inhibit neuroinflammation and oxidative stress in TBI rats by down-regulating RhoA/ROCK signal pathway, thereby reducing the damage of blood brain barrier and repairing its neural function.