Background: Intensive blood pressure (BP) reduction is regarded as the gold standard therapy for acute intracerebral hemorrhage (ICH), but its associations to cerebral hypoperfusion and ischemic lesions have been suspected. This study aims to investigate the impact of acute BP reduction on the development of acute ischemic lesions (AILs) at border zone (BZ) areas in patients with hypertensive ICH. Methods: We enrolled patients with acute hypertensive ICH (hemorrhagic lesions restricted to deep region [Strictly deep-ICH] or located in mixed lobar and deep areas [Mixed-ICH]) who received brain MRI within 7 days after ICH onset. BZ AILs were defined as lesions locating at BZ areas that were hyperintense on DWI sequence and hypointense on ADC series (figure). Acute SBP change was the difference between the initial SBP and the SBP recorded at 24 hours after ICH onset. Results: Of the 274 enrolled patients (62.5 ± 12.7 years old, 65% male), 11 subjects had BZ AILs. Compared to patients without BZ AILs, patients with lesions had wider amount of acute SBP reduction (71.7 ± 33.6 vs. 43.0 ± 32.2 mmHg, P = 0.023), more lobar and deep microbleeds (MB) and larger white matter hyperintensity volume (all p < 0.05). Using ROC curve analysis, acute SBP drop at more than 54mmHg was linked to the occurrence of AILs (sensitivity 82%, specificity 64%, P = 0.002). In multiple logistic regression model, acute SBP decline at above 54mmHg (OR 11.45, 95%CI 2.06 - 63.49, P = 0.005) and higher deep MB burden ( P = 0.032) raised the risk of AILs after adjustment for age, sex, and image markers of cerebral small vessel disease. In subgroup analysis, larger acute SBP drop remained to be an independent risk factor for development of AILs in patients with Mixed-ICH ( P = 0.008), but not in patients with strictly deep-ICH ( P = 0.715). Conclusion: Acute SBP change in hypertensive ICH, especially in Mixed-ICH, increases the risk of AILs at BZ areas, showing widespread microangiopathy that is vulnerable to rapid BP dysregulation to ischemia.