Abstract： Objective To introduce the technique of interictal 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) examination and explore the value of 18F-FDG-PET in the localization of epileptogenic focus of temporal lobe epilepsy (TLE) confirmed by surgical result.Methods Clinical data were retrospectively analyzed in 82 TLE patients having received interictal 18F-FDG-PET preoperative evaluation and got EngleⅠ grade epileptic surgical outcome, and the sensitivity and specialty of interictal 18F-FDG-PET were compared with those of MRI and scalp video-EEG. Results Epileptogenic foci showed hypometabolism on 18F-FDG-PET, and the hypometabolism zones were localized in ipsilateral temporal lobe in 68 cases,beyond ipsilateral temporal lobe in 9 cases; the other 5 had no hypometabolism zone. Accuracy rate of localization of epileptogenic foci by interictal 18F-FDG-PET was 82.9% (68/82), significantly higher than that by MRI or EEG(P＜0.05).77.4%(41/53)epileptogenic foci where MRI showed negative and 75%(15/20)where EEG with imbedded electrode was applied were precisely localized by 18F-FDG-PET. The accuracy was higher in the cases with positive pathological result than in the ones with negative result. Conclusions Interictal 18F-FDG-PET possesses excellent sensitivity and specialty in preopemtive assessment for TLE, and is of good value in the localization of epileptogenic focus where MRI shows negative or invasive electrophysiologic monitoring is needed.Rational application may raise the accuracy rate.