Abstract: Objective :To investigate the effects of fentanyl-TTS (transdermal fentanyl, Durogesic)on the treatment of moderate cancer pain and the indication of administration for these patients. Methods :98 adult patients with cancer pain were selected. The pain assessment score of visual ana-logue scale(VAS) was between 4 to 6. Fentanyl-TTS was administered from the dosage of 2.5mg. Alter-nation of Fentanyl-TTS was three days and the duration of treatment was 15 days. The score of VAS,side-effect of Fentanyl-TTS were observed during the procedure. Results :VAS before research wassignificantly higher than that after treatment of fentanyl-TTS (P<0.01). Constipation, nausea, vomiting,dizzy and drowsiness were common symptoms of side-effects. Conclusion :Moderate cancer pain couldbe well treated with fentanyl-TTS with a favourable safety profile. The indications was the patientswhom the VAS was between 4 to 6 and cancer pain was bad treated with 1st and 2nd ladder anal-gesics.