Objective The quantitative pharmacoelectroencephalography ( QPEEG ) of many antiepileptic drugs (AEDs), such as carbamazepine, valproic acid, phenobarbital and topiramate but not levetiracetam (LEV), have been studied. This study is to investigate the effect of LEV on QPEEG. Methods One dose of LEV at l g was administrated to 12 healthy adults (6 males, average age at 26 years, average height at l.67 m). The EEG samples (of 180 seconds each) were obtained prior to and at regular intervals ( 1, 1.5, 2, 3, 4, 6, 7, 8, 12, 24 hours) after administration of LEV. The EEG activity was processed with the power spectral analysis and separated into different frequency bands. The absolute powers of both occipital and frontal lobes were calculated through 30 seconds epochs without artifacts for each recording. The statistical difference between baseline pre-drug control and each post-drug assessment was evaluated by the Wilcoxon matched-paired rank test. Results The power of α1-band and β-band increased bilaterally over both frontal and occipital lobes after the administration of LEV. There was no change of α2-band over bilateral frontal lobes, but increased in double peaks shape with the low point at the 6 hours after the administration. The power of α1-band showed the significant change after the administration at the 1.5 hours (18.8950, Z= -3.059, P=0.002) in the left front, 3 hours (18.6150, Z= -2.981, P =0.003)in the right front, 1.5, 2, 3 and 4 hours (61.0233, 53.9425, 47.6192 and 51.8250 respectively, Z =-3.059, -3.059, -2.903 and -3.059, all P ＜ 0.01 ) in the left occipital, and 1, 1.5, 2 and 3 hours (53.5358, 56.8092, 50.3500 and 47.1733 respectively, Z = -2.903, -3.059, -3.059 and -2.981,all P ＜ 0.01 ) in the right occipital. The power of α2-band showed the significant change after the administration at the 3 hours (73.5450, Z = - 3.059, P = 0.002) in the left occipital, and 1, 3 hours (80. 6808 and 87. 1750, Z = -2.903 and - 3.059, P = 0.004 and 0.002 respectively ) in the right occipital. The power of β-band showed the significant change after the administration at the 3 hours (3.8000, Z = -3.059, P = 0.002) in the left front, 1.5, 2 and 3 hours (4.0408, 4.3217 and 4. 1050,Z= -2.903, -3.059 and -3.061, all P＜0.01) in the right frontal, 3 hours (9.1408, Z= -3.059,P =0.002) in the left occipital, and 1.5, 3 hours (8.9267 and 9.3033, Z = -2.981 and -2.981, both P = 0.003) in the right occipital. Conclusions LEV can change the background activity of QPEEG. The changes are different from those of the other AEDs.