In order to distinguish the functional connectivity on different brain areas between two mental states of lying and telling-truth and to research this functional connectivity change in time-frequency domains,forty healthy right-handed subjects with an average age of 21 were randomly divided into two groups (20 each): Lying and telling-truth. Through standard three stimuli paradigm, we recorded the 12 channels electroencephalogram ( EEG) signalsin two states. Then, used wavelet coherence method to calculate the coherence coefficient on66 pairs of channelsof the following time-frequency bands:θ(0. 5 ~ 4Hz)、δ( 4 ~ 8Hz)、α( 8 ~ 13 Hz)、β( 13 ~ 30 Hz)、γ (30~ 100 Hz) and the time range of 250 ~ 1 300 ms after the stimuli ( typical occurrence time of P300). Analyzed the functional connectivity on different channels pairs in different time-frequency areas. Finally, Wilcoxon test was used to compare the difference of wavelet coherence on the same time-frequency domain between the two groups of the subjects. The experimental resultshows that in the time-frequency domain corresponding to frequency bands θ and δ, there were statistical differences in the coherence values of OZ-P4,OZP3 and P3-P4of the two groups of subjects. The finding indicates that when lying with physicalevidence, the associative visual cortex(P3 and OZ) and inferiorparietallobule ( P4) may be activated during utilitarian and nonutilitarian moral judgments, yielding significant statistical differences in the functional connectivity between different brain regions.