Objective Aimed to clarify the molecular mechanism after subarachnoid hemorrhage （SAH） by investigating the expression of tight junction protein Claudin-5 and ZO-1 and the effects of SP600125 on them. Methods Seventy-five male Sprague Dawley rats （300 to 350 g） were randomly divided into sham,SAH,SAH ＋ DMSO （dimethyl sufoxide） solution,SAH ＋SP600125 （C-Jun N-terminal kinase inhibitor）10 mg/kg,and SAH ＋SP600125 30 mg/kg groups. The standard endovaseular perforation was performed to produce experimental SAH. The JNK inhibitor SP600125 was intraperitoneally administered at 1 hour before and 6 hours after SAH. Results At 24 hours after SAH,signs of microvessels injury were observed in brain cortex. Compared with the sham group,expression of Claudin-5 and ZO-1 was sig- nificantly decreased （P 〈 0.05 ）. JNK inhibitior SP600125 suppressed the decrease of Claudin-5 and ZO-1 expression, attenuated blood-brain barrier disruption in rats after SAH. Conclusions The blood-brain barrier disruption is an important mechanism of early brain injury after SAH. JNK inhibitor SP600125 improves neurological outcomes and provides neuropmtecfion against acute events after SAH such as bloodbrain barrier disruption and cell apoptosis.