Abstract: Objective: To compare the anesthesia effects and security of different dose of fentanyl injection combined sevflurance inhalational anesthesia by larygeal mask airway(LMA) in the ureteroscope pneumatic lithotripsy(URSL). Methods: Eighty patients, classified ASA Ⅰ-Ⅱ,scheduled for the selective surgery of URSL,were randomly divided into four groups with 20 cases each. Group A was given total sevoflurane inhalational anesthesia, Group B、C、D received intravenous fentanyl 1,2 and 4 μg/kg respectively, 2 minutes before sevflurance inhalational anesthesia induction was implemented. The vital signs such as heart rate(HR)、mean arterial pressure(MAP),arterial oxygen saturation(SpO₂) and end-tidal pressure of carbon dioxide(P_ETCO₂) were monitored during anesthesia, and induction time, awakening time, intraoperative medication, body motion were recorded. Meanwhile, the complications such as respiratory depression, postoperative dizziness, nausea and vomiting were observed. Results: Four groups underwent the operation smoothly,and awareness with recall during general anesthesia didn't occur. After induction,MAP of four groups declined (P < 0.05-P < 0.01),MAP of Group D dropped more than that of A,B and C(P <0.05-P <0.01). HR of Group D was decreased temporarily (P < 0.05). There was no statistically significant difference in the incidence of respiratory depression between Group A,B,C and D(P > 0.05). SpO₂ after induction was decreased slightly in Group D(P < 0.01),while P_ETCO₂ was increased(P < 0.05). The induction time in Group A was longer than C and D(P < 0.05-P < 0.01),and the awakening time was not different in the four groups(P > 0.05). The dose of sevoflurane in Group C and D was lower than in A(P < 0.01),the incidence of postoperative nausea and vomiting in Group A was higher than B,C and D(P < 0.05). When the LMA was inserted,there was body motion happened in A and B. Conclusions: The application of fentanyl injection combined sevoflurane inhalational anesthesia by LMA in the URSL is effective and safe. Fentanyl wes given 2 minutes before sevflurance inhalational anesthesia induction,which can shorten the induct time,lower the dose and side effects of sevflurance. When the dose of fentanyl is or over 4 μg/kg,the influence of respiration and circulation will happen.