\[Abstract\]ObjectiveTo assess the clinical effect of modified Mapleson D breathing system in intravenous anesthesia for minor surgical procedures. MethodsA total of 112 patients (ASA Ⅰ-Ⅱ) scheduled for minor outpatient surgery were randomly divided into two groups,with 56 in each group. Patients in Group A inhaled oxygen using common face mask, and were transferred to artificial ventilation by emergency ventilator when respiratory depression occurred; those in Group B were subjected to modified Mapleson D breathing system, and were transferred to artificial ventilation using the present breathing system when respiratory depression occurred. The respiratory rate (RR), oxygen saturation (SpO2), Partial end-tidal CO2 pressure (PETCO2), occurrence (T1) and rectification time (T2) of respiratory depression were all recorded in the two groups.ResultsThe incidence of respiratory depression in Group B was lower than that in Group A; moreover, Group B also had a higher incidence of hyoxemia and shorter rectification time compared with Group A. ConclusionCompared with conventional face mask, our modified Mapleson D breathing system is easy and convenient to use, and it leads to lower incidence and quick rectification of respiratory depression, showing a potential in the airway management of patients undergoing minor intravenous anesthesia.