Abstract： Objective To investigate the feasibility and safety*with the low dose fentanyl for valve replacement fast track cardiac anesthesia. Methods 40 cases with cardiac valve replacement were divided into two groups,group Ⅰ :20 cases with fast track anesthesia,group Ⅱ :20 cases with large dose fentanyl anesthesia. The blood presure, HR, SpO2, CVP,Temperature, airway pressure were observed at different time points. The postoperative extubation time,ICU stay,hospital stay,postoperative pulmonary complications were recorded. Results The fentanyl(μg/kg) of group Ⅰ (23. 25 ± 1.32) was less than that of group Ⅱ ( 35.75 ± 6. 84) ( P < 0. 05 ); Extubation time (hours), ICU stay ( hours),length of stay (days) were ( 7.92 ± 3. 16), (25. 12 ± 7.50), ( 28.50 ± 8. 94 ) in group Ⅰ , and that were (13.70±5.63) ,(37.53 ±13. 19) ,(38.00 ± 12. 90) in group Ⅱ. The group Ⅰ were shorter than the group Ⅱ ,P<0. 05; There were four cases of lung infection in group Ⅱ, no one in group Ⅰ ( P < 0. 05 ); There were significant differences between the two groups. There were no significant differences in the remaining observations. Conclusion The low dose fentanyl anesthesia for fast track anesthesia in heart valve replacement surgery was reliable and safe;It could help to reduce postoperative extubation time, ICU stay time and hospital stay time and reduce postoperative pulmonary complications and hospital costs.