This study was aimed to investigate the changes of brain MRI features and serum biological parameters in patients with TLE. 30 patients with unilateral TLE confirmed by surgical pathology were selected as study subjects, and 30 subjects without a history of epilepsy who underwent health examinations during the same period were selected as controls. The brain MRI features of the patients were explored and the T2 relaxation time (HCT2) indexes of the bilateral hippocampus were extracted. The differences in levels of peripheral blood T lymphocyte subsets, inflammatory cytokines, and miRNAs were measured. The results showed that the hippocampal volume of TLE patients was significantly reduced, and the HCT2 value of the hippocampus was greater than that of the control group ( P < 0.05 ). CD3+ (77.9 ± 4.4)%, CD4+ (45.6 ± 2.2)%, CD8+ (22.1 ± 1.9)%, and CD3+/CD8+ (2.24 ± 0.22) in peripheral blood T lymphocyte subsets of epileptic patients, compared with control group, CD3+, CD4+, and CD4+/CD8+ levels were significantly increased and CD8+ concentration was significantly decreased in epileptic patients ( P < 0.05 ); inflammatory cytokines TNF-α was (2.63 ± 0.26) pg/mL, IL-1β was (4.61 ± 0.57) pg/mL, IL-2 was (1.59 ± 0.21) pg/mL, IL-6 was (2.28 ± 0.19) pg/mL, and ICAM-1 was (1.89 ± 0.30) pg/mL in peripheral blood of epileptic patients, which was significantly increased compared with control group, while IL-10 was significantly decreased in epileptic patients ( P < 0.05 ); miR-146a was (2.14 ± 0.28) and miR-210 was (1.89 ± 0.31), miR-221 (2.44 ± 0.35), miR-34a (0.59 ± 0.14), miR-135b (10.17 ± 0.16), miR-33 (0.26 ± 0.09) in peripheral blood miRNA levels of epileptic patients, and miR-146a, miR-210, miR-221, and miR-34a levels of epileptic patients were significantly increased compared with control group, while MiR-135b and miR-33 levels of epileptic patients were significantly reduced ( P < 0.05 ). In summary, patients with TLE have hippocampal lesions, which may be related to peripheral blood T lymphocyte subsets imbalance, chronic inflammatory response, and abnormal expression of miRNAs.