Objective: To analyze the changes of hippocampus blood perfusion and hippocampal volume in patients with temporal lobe epilepsy (TLE) caused by hippocampal sclerosis (HS) using single- photon emission-computed tomography (SPECT) and MRI, so as to explore the effect on localization of epileptogenic focus in TLE patients. Methods: Eighteen TLE patients and 3 healthy controls underwent 99Tcm-ethyl cysteinate dimer (99Tcm-ECD) SPECT. Eighteen TLE patients and 21 healthy controls were performed MRI. The relative cerebral blood flow (rCBF) and hippocampal volume were calculated and compared between 2 groups. The correlation between rCBF in ipsilateral hippocampus and hippocampal volume of TLE patients was analyzed. Results: SPECT showed rCBF in ipsilateral hippocampus [(46.04 ± 7.94) ml/(100 g·min)] was significantly decreased compared with contralateral hippocampus in TLE patients [(54.76 ± 9.62) ml/(100 g·min); t =-2.966, P = 0.005] and bilateral hippocampus in healthy controls [(64.87 ± 7.28) ml/(100 g·min); t =-4.824, P = 0.000]. The volume of ipsilateral hippocampus [(1.69 ± 0.39) cm3] was significantly smaller than that of contralateral hippocampus in TLE patients [(2.68 ± 0.41) cm3; t =-7.410, P = 0.000] and bilateral hippocampus in healthy controls [(3.50 ± 0.39) cm3; t =-16.340, P = 0.000]. The rCBF of ipsilateral hippocampus had positive correlation with the volume of corresponding hippocampus in TLE patients (r = 0.394, P = 0.017). Conclusions: Both rCBF and the volume of ipsilateral hippocampus were reduced in patients with TLE caused by HS, and there was positive correlation between the two. It was helpful for preoperative localization of epileptogenic focus to combine SPECT with MRI. Copyright © 2015 by the Editorial Board of Chinese Journal of Contemporary Neurology and Neurosurgery.