Objective: To evaluate the efficacy of WEI NASAL JET for supraglottic ventilation before tracheal intubation in the patients with tooth loss. Methods: Sixty patients of both sexes with tooth loss (more than 8 teeth missing), aged 67-83 yr, of American Society of Anesthesiologists physical statusⅠ-Ⅲ, with Mallampati classificationⅠ-Ⅲ, with body mass index of 18-25 kg/m², undergoing surgery with general anesthesia, were divided into 2 groups (n=30 each) using a random number table method: WEI NASAL JET group (S group) and mask group (M group). After the end of anesthesia induction, WEI NASAL JET was inserted via the nasal cavity to perform supraglottic ventilation in group S, and two-hand buckle mask was performed in group M, and the patients were tracheally intubated after 5-min ventilation.At 5-min spontaneous breathing after nitrogen removal by oxygen supply, 1, 2, 3 and 4 min after no spontaneous breathing and immediately after intubation (T₅), ultrasound was used to measure the amplitude of diaphragm motion induced by respiratory movement, and blood gas analysis was performed to record the development of pH value<7.30, SpO₂<90% and fluctuation in mean arterial pressure and heart rate ≥30% of baseline before operation.The development of ventilation-related complications was also recorded. Results: Compared with group M, the amplitude of diaphragm motion induced by respiratory movement was significantly increased at T_1-5, PaO₂was increased at T_2-5, PaCO₂ and P_ETCO₂ were decreased at T_3-5, the incidence of sore throat and nasal mucosal bleeding was increased, the incidence of gingiva injury and flatulence was decreased (P<0.05), and no significant change was found in the incidence of fluctuation in mean arterial pressure and heart rate ≥30% of baseline in group S (P>0.05). The pH value<7.30 and SpO₂<90% were not found in two groups. Conclusion WEI NASAL JET can provide satisfactory supraglottic ventilation efficacy before tracheal intubation with good safety in the patients with tooth loss.