To compare the effects and mechanism of different doses of urokinase on the blood-brain barrier (BBB) in rats of intracerebral hemorrhage (ICH). Methods: We selected 40 adult male Wistar rats and established the ICH model by autologous blood injection into the caudatum. After successful modeling, they were randomly divided into 4 groups, each with 10 rats: the control group and the low dose (30000 U/mL), medium dose (50000 U/mL), and high dose (100000 U/mL) urokinase groups, respectively named the ICH group and L, M, and H dose groups. Three hours after establishment of the model, different doses of urokinase were injected into the hematoma respectively, and the rats in the ICH group received the same amount of normal saline. Three days after modeling, the brain water content was measured by the dry/wet weight method, the BBB permeability was evaluated by Evans blue fluorescence, and the expression levels of zonula occludens-1 (ZO-1) and matrix metalloproteinase-9 (MMP-9) in brain tissues around the hematoma were detected by Western blot. Results: Compared with the ICH group, the L, M, and H dose groups showed a decreased water content in brain tissues surrounding the hematoma (all P<0.05), reduced EB dye permeation out of blood vessels in brain tissues (all P<0.05), and up-regulated ZO-1 (all P<0.05) and down-regulated MMP-9 (all P<0.05) in brain tissues. Furthermore, the L dose group exhibited the lowest water content in tissues surrounding the hematoma, the least EB dye seepage from blood vessels, the highest ZO-1 expression, and the lowest MMP-9 expression, with results being significantly different from those of the M and H dose groups (all P<0.05). Conclusion: The injection of 300 U urokinase into hematoma serves to protect the integrity of the BBB after ICH, and the mechanism may involve increasing ZO-1 and decreasing MMP-9 expression.