Abstract: Objective :To observe the analgesic efficacy of Transdermal fentanyl (TDF) in patientswith chronic and stubborn pain. Methods :Four-hundred and sixteen cases of the ambulatory clinicwere enrolled in this study on treatment with TDF, of which 314 were suffering from medial or latecancer pain and 102 were of non-cancerous pain. The intensity of pain (measured by visual analoguescale, VAS), quality of life, side effect of TDF before and after treatment were observed and compared. Results :VAS decreased significantly from 7.94±1.15 to 1.64± 1.71 after treatment in patients with can-cerous-pain, and from 7.30±1.54 to 1.91±1.53 in non-cancer patient. In cancer patients, 51.5% wasmarkedly relieved from pain, of 19.7% was free from pain, and total relief rate accounted for 71.2%. Innon-cancer patients reached 45%, 13.7%, and 58.7% respectively. The quality of life in both patientsimproved significantly (P<0.01).The side-effect of TDF was similar to other opiates: mainly dizziness,nausea and vomiting, but they were mild. No occurrence of respiratory depression, physical or mind de-pendence after stopping treatment. Conclusion :TDF possesses characteristics of noninvasive route ofadministration, continued release of the drug, valid analgesic effect, mild side-effect, good complianceof patients and is suitable for application in out-patients clinic or family.