Recent studies have shown that telmisartan (TMS) is effective for the protection against ischemia/brain damage in rat models. However, the specific underlying mechanism is poorly understood. In line with previous results, our data showed that TMS improves CBF and physiological variables, including pH, pCO2, pO2. Through CD31 immunofluorescence staining, reduction of blood vessel density was found in MCAO group, but TMS treatment could enhance the cerebral vascular density in the ischemic area. Meanwhile, TMS treatment could enhance the number of BrdU/lectin double-positive cells. Furthermore, the reduction of nestin-positive cells was identified in the brain of MCAO rats, while the number of nestin-positive cells was significantly increased after TMS administration. Furthermore, the expression of ERS-related proteins, including GRP78, CHOP/GADD153, Caspase12 was increased after MCAO, but was decreased after administration of TMS, thereby enhancing angiogenesis and neuron regeneration.