Early detection of ischemic stroke is essential for initiating treatment before irreversible brain injury occurs. This study aimed to identify novel serum biomarkers capable of detecting ischemic stroke in early stages, prior to the development of severe brain damage caused by cerebral artery occlusion. Male Sprague-Dawley rats (9 weeks old; n= 3 per group) underwent middle cerebral artery occlusion for 0 minutes (sham), 30 minutes (0.5 hour), 1 hour, 2 hours, or 3 hours. Next-generation sequencing of brain tissue identified integrin subunit alpha M (Itgam ; CD11B), C-C motif chemokine ligand 2 (Ccl2), and alpha-2-macroglobulin (A2m) as candidate biomarkers. Western blot validation analysis revealed that CD11B and CCL2 levels progressively increased in both brain tissue and serum, correlating with occlusion duration and the extent of brain damage. In contrast, A2M expression decreased in brain tissue but increased in serum with longer occlusion times. Notably, in the 0.5 hour occlusion group, no visible brain damage was observed by 2,3,5-triphenyltetrazolium chloride staining; however, serum levels of CCL2 and A2M were significantly elevated compared to the sham group. These findings suggest that CD11B, CCL2, and A2M are promising early biomarkers for ischemic stroke. Increases in their serum concentrations occur at the earliest stages of ischemia, potentially enabling early diagnosis and therapeutic intervention before irreversible brain damage becomes detectable by conventional imaging techniques.