Objective To explore the value of 64 slice spiral CT and neuropsychological test in the evaluation of cognitive function in patients with insomnia. Methods A total of 28 patients with primary insomnia （case group） and 28 healthy controls （control group） were selected. Pittsburgh Sleep Quality Index （PSQI）， Wisconsin Card Sorting Test （WCST）， Clinical Memory Scale （CMS）， frontal index and hippocampus index were measured. Results WCST score showed that the number of tests completed and the number of items to be answered in the first category in the case group were more than those in the control group （t=2.107， 2.349；P=0.04，0.023）. CMS showed that the scores of portrait characteristics， associative recall， meaningless graphic reconfirmation， directed memory and total memory quotient in the case group were lower than those in control group （t=6.761，5.901，3.034，12.533；P ＜ 0.01）. There was no significant difference in frontal angle index and hippocampus index between case group and control group （t=1.128，0.652；P=0.264，0.517）. PSQI was significantly positively correlated with the number of tests completed and the number of responses to the first classification in WCST （t=0.675，0.731；P ＜ 0.01）， and negatively correlated with the image characteristics， associative recall， meaningless figure reconfirmation， directed memory and total memory quotient in CMS （t=- 0.612，-0.604，-0.623，-0.714；P＜ 0.01）. Conclusions WCST and CMS indicate cognitive dysfunction in patients with insomnia， but 64 slice spiral CT does not find the corresponding objective evidence.