Test anxiety is associated with impaired attentional control, and spontaneous electroencephalography (EEG) theta/beta power ratio (TBR) may reflect the cortical–subcortical interactions involved in attentional control. The present study investigated how test anxiety influences spontaneous EEG TBR. Individuals undertook a 10-minute Raven's intelligence test. Spontaneous EEG data were recorded before and after the test and subsequently analyzed. TAS score showed a significant positive correlation with parietal EEG TBR before the test. Individuals with high test anxiety exhibited a significantly larger parietal EEG TBR than did individuals with low test anxiety, both before and after the test. The findings suggest that parietal spontaneous EEG TBR is related to test anxiety and can distinguish between individuals with high and low test anxiety.