Abstract： Objective:A voxel-based morphometry(VBM)was used to investigate the abnormal patterns of gray matter volume of cerebellar subregions of type 2 diabetes mellitus(T2DM)patients using spatially unbiased infratentorial template for fine subregion segmentation of the cerebellum.Materials and Methods:Seventy-five patients with T2DM and 53 healthy controls(HCs)were recruited,and collected cranial MRI image data,clinical data,and cognitive-psychological scales from all subjects.Differences in gray matter volume in cerebellar subregions between T2DM and HCs were compared by independent samples t test,and Pearson or Spearman correlation analysis was performed with clinical data and scores of cognitive-psychological scales in differential cerebellar subregions.Results:Compared with HCs,T2DM patients had lower Montreal Cognitive Assessment scores and higher 24-item Hamilton Depression Scale and Hamilton Anxiety Scale scores(P＜0.001).Reduced gray matter volume in the right cerebellar Crus Ⅰ and bilateral cerebellar lobules Ⅰ-Ⅴ/Ⅰ-Ⅳsubregions(voxel level P＜0.001,cluster size＞100).The body mass index was positively correlated with right lobules Ⅰ-Ⅴ(r=0.265,P= 0.022),left lobules Ⅰ-Ⅳ(r=0.323,P=0.005)subregions gray matter volume,and gray matter volume in right Crus Ⅰ subregion was negatively correlated with fasting insulin levels(r=-0.263,P=0.023)and updated homeostasis model assessment insulin resistance index(r=-0.327,P=0.004).Conclusions:Patients with T2DM are at risk for mild cognitive impairment and depression and anxiety,and reduced gray matter volume of right Crus Ⅰ may be associated with insulin resistance.