Background and aims: Monocytes/macrophages play important roles in inflammatory bowel disease and depression, but few studies had focused on the change of monocytes/macrophages in ulcerative colitis (UC) patients with psychiatric disorders. Methods: UC patients were divided into two groups based on the Hospital Anxiety and Depression Scale (HADS). Demographic and clinical data were captured. Peripheral blood samples and intestinal biopsies were collected for the analysis of monocyte immunophenotype, phagocytic function, and CD4 + T cell differentiation. Transmission electron microscopy was used to observe the ultrastructure of intestinal macrophages. Results: A total of 139 UC patients were included. 37.41% and 32.37% of UC patients had symptoms of anxiety and depression. In patients with symptoms of anxiety/depression, mayo score, platelet count, erythrocyte sedimentation rate, and endoscopic score, histological scores were significantly higher than those in UC patients without. In patients with symptoms of anxiety/depression, the percentages of CD14 + + CD16 + monocytes and CD14 + CD16++ monocytes were higher, and the phagocytosis was decreased. Patients with symptoms of anxiety/depression had more CD68 + cells and higher M1/M2 ratios in the intestine mucosal layer compared to those without. Conclusions: Monocytes and intestinal macrophages from UC patients with anxiety/depression tended to polarize to pro-inflammatory subtypes, and their function was also impaired.Keywords: Macrophage; Macrophage colony-stimulating factor; Monocyte; Ulcerative colitis.