Objective: This study aims to study the biological and biomechanical characteristics of the middle cerebral artery (MCA) in aged and estrogen-intervened aged rats, thereby providing biomechanical basis for clinics. Materials and Methods: Thirty 18-month-old Sprague Dawley (SD) rats, 30 18-month-old estrogen-intervened SD rats, and 30 four-month-old SD rats were studied. The estrogen-intervened rats were given estradiol benzoate on the fifth feeding day. Thirty-four days after the feeding, the serum of each rat was obtained. The radioimmunoassay was performed for the content determination of serum E2, ER, malondialdehyde (MDA), and superoxide dismutase (SOD). The tensile test was performed to evaluate the MCA of each rat. Results: Through the estrogen intervention, the serum contents of E2, ER, SOD, and MDA in old rats were restored to normal levels. The maximum stress, maximum strain, and elastic limit of the MCA in the aged estrogen- intervened rat group were greater than those of the non-intervened aged rat group, with a significant difference (p < 0.05). The elastic modulus in the aged estrogen-intervened rat group was less than that of the non-intervened aged rat group, with a significant difference (p < 0.05). Conclusion: E2 intervention can improve the flexibility, toughness, and compliance of MCA in aged rats.