Objective:To investigate the significance of CT imaging features in the diagnosis of first-episode paranoid schizophrenia.Methods:Forty-five patients with first-episode paranoid schizophrenia admitted to Shaoxing 7 th People's Hospital from January 2018 to January 2019 were included in the study group. An additional 40 healthy controls who received health examination were included in the control group. All participants underwent head CT scans and CT values of cerebral lobes were measured. CT imaging features of first-episode paranoid schizophrenia were analyzed. The recurrence rate of paranoid schizophrenia was calculated. The diagnostic effect of CT imaging on paranoid schizophrenia was evaluated. Results:The CT value of the frontal lobe in the study group was significantly lower than that in the control group [(33.1 ± 1.4) HU vs. (36.9 ± 2.1) HU, t = 9.914, P < 0.001]. The proportions of patients having ventricular enlargement, sulcus widening, arachnoid cyst and cisterna magna in the study group were 51.1%, 24.4%, 31.1% and 20.0% respectively, which were significantly higher than 5.5%, 2.5%, 2.5% and 2.5% respectively in the control group ( χ2 = 21.688, 8.411, 11.928, 4.675, all P < 0.05). The recurrence rate of paranoid schizophrenia in the study group was 22.2% (10/45). The CT value of the left and right frontal lobe in patients with recurrent paranoid schizophrenia was (32.1 ± 1.7) HU and (32.5 ± 1.6) HU respectively, which was significantly lower than (35.0 ± 1.9) HU and (34.9 ± 1.7) HU in patients without recurrent paranoid schizophrenia ( t = 4.348 and 3.985, both P < 0.001). Conclusion:Patients with first-episode paranoid schizophrenia have brain structural abnormalities, as manifested by ventricular enlargement, sulcus widening, arachnoid cyst, and cisterna magna. CT imaging features are of great value in the diagnosis of first-episode paranoid schizophrenia. It deserves wide popularization and has a great innovation value.