Abstract: Objective To investigate the feasibility of high-frequency ultrasound for the diagnosis of diastasis recti in postpartum women by assessing the inter-rectus distance （IRD） in healthy nulliparous woman and postpartum women. Method 150 healthy nulliparous volunteers （nulliparous group） and 167 postpartum women （postpartum group） were included in the study. IRD was measured at the 3 cm below the umbilicus, umbilicus and 3 cm above the umbilicus in a supine position using a high-frequency line array probe. The IRD at three sites between the two groups was compared. The 90^th, 95^th, and 99^th percentiles of normal values of the rectus abdominis spacing obtained in the nulliparous group were used as diagnostic cut-off values for diastasis recti, and the morbidity of postpartum group was observed at different cut-off values. Results In a supine position, the IRD at 3 cm below the umbilicus was 0 （0, 1.00）mm, 11.00（7.00, 16.00）mm at the umbilicus, and 6.00（2.00, 9.00）mm at 3 cm above the umbilicus in the nulliparous group, and 4.00 （0, 12.00） mm, 27.00 （20.00, 33.00）mm and 23.00（17.00, 29.00） mm in the postpartum group, respectively. There was significant difference in the IRD at three sites between two groups （all P < 0.001）. Taking the 90^th, 95^th and 99^th percentiles as the diagnostic cut-off values, the prevalence rates of diastasis recti in the postpartum group were 93.4%, 85.6% and 68.3%, respectively. Conclusion IRD multipoint measurement by high-frequency ultrasound is highly feasible for diagnosing diastasis recti in postpartum women.