Abstract: In this research, the relationship between electroencephalogram（EEG） of intellectual activity and Intelligence Quotient（IQ） on time domain and frequency domain were explored. 43 students who fell into 18～ 25 year-old range were selected as subjects. The IQ scores were calculated according to the Wechsler Adult Intelligence Scale（WAIS-R）. Brain wave signals were recorded by using NeuroScan Brain Wave Detection System. Furthermore the sum of EEG energy in each channel was calculated in the time domain, and the EEG energy produced by intellectual activity distribution over the brain was observed. Then, using Fast Fourier Transform for time-frequency conversion, the intensity distribution of EEG signal at each frequency was compared in the frequency domain. Finally, the relationship between IQ and EEG in the distribution patterns of alpha and beta bands was judged through the analysis of variance and other methods. The results showed that EEG energy was mainly distributed in18 electrodes, which were FC6, F6, FC5, etc. There was a negative correlation between the EEG energy and the IQ score. In frequency domain, there was a linear relationship between IQ and EEG amplitudes on alpha and beta bands which provided a reference for predicting IQ by using EEG signals. This research explored the relationship between IQ and time-frequency characteristics of EEG, provided insights for further study in the field of understanding the relation between IQ and EEG signals.