Objective:To explore the applicability of three-dimensional transvaginal ultrasonography (3D-TVS) in the evaluation of diminished ovarian reserve (DOR) and premature ovarian failure (POF).Methods:One hundred and twenty female patients, who received 3D-TVS in our hospital from January 2020 to March 2022, were included in the study. Based on sex hormone examination, 25 cases were DOR (DOR-group), 32 cases were POF (POF-group) and 63 cases had normal ovarian function (Normal-group). The 3D-TVS quantitative examination results of the three groups of patients were analyzed and compared.Results:There was no significant difference between the DOR-group and POF-group regarding antral follicles count (AFC), ovarian volume (OV), vascularization index (VI), vascularization flow index (VFI) and flow index (FI) of left and right ovaries (p>0.05). Compared with the Normal-group, the 3D-TVS examination indexes of the DOR-group and POF-group were significantly lower, and the 3D-TVS examination results of the POF-group were significantly lower than those of the DOR-group (p<0.05). Using sex hormone examination as the gold standard, the diagnostic specificity of 3D-TVS for DOR was 80%, and the sensitivity and accuracy were 90% and 88% respectively; The diagnostic specificity of POF was 87.5%, the sensitivity and accuracy were 95.8% and 93.8% respectively.Conclusion:3D-TVS can provide scientific guidance for the clinical diagnosis and evaluation of DOR and POF.