Abstract： [Objective]To explore the distribution and expression changes of tight junctional protein JAM-1 in rat models after intracerebral hemorrhage (ICH) and their significance.[Methods]One hundred and twenty-eighty healthy male SD rats were randomly divided into normal control group (n=16) and ICH group (n=112),and the ICH models were induced by stereotactically injecting 75 uL autologous blood into the right caudate nucleus.Seven time points after ICH (6,12,24 and 48 h,and 3,7 and 14 d after ICH,16 rats for each time point) were chosen.BBB permeability was evaluated by Evans blue dye extravasation.The distribution and expression of JAM-1 were detected by immunofluorescence and real-time quantitative PCR.[Results] As compared with that in the normal control group,BBB permeability in the ICH group significantly increased at 24 and 48 h,and 3 and 7 d after ICH (P＜0.05).JAM-1 expression decreased at blood vessels at 12,24 and 48 h after ICH,and JAM-1 expressed at the circulatingleukocytes3 dafterlCH,and abundant JAM-1 positive cells around hematoma were noted in the ED-l-positve macrophages 7 d after ICH.JAM-I mRNA significantly decreased at 12,24 and 48 h after ICH,and significantly increased 7 d after ICH as compared with that in the normal control group (P＜0.05).[Conclusion] JAM-1 experssion changes not only participate in regulation of BBB permeability but also play roles in inflammatory insult after ICH.