Abstract: To evaluate the efficacy and adverse side effects of oxycodone hydrochloride controlled - release tablets in the treatment of moderate to severe pain in patients with terminal cancer and to observe any improvement on the cancer patients' quality of life. Methods: Sixty- eight patients with moderate or severe cancer pain were treated with oxycodone hydrochloride controlled- release tablets. The initial dose was 5mg/12h, or 1/2 that of the standard morphine regimen. During the course of treatment, the dosage was adjusted according to the patients' desires until the pain completely disappeared or nearly did so. Each patient received the treatment for at least 15 days. At the same time, adverse effects, quality of life and scores for the intensity of pain were observed and recorded.Results: The final titrated dosage of oxycodone was as follows: the patients in 30 cases (44.1%) received a dosage of ≤30 mg/d, those in 16 cases (23.5%) received a dosage of 31 to 60 mg/d, those in 18 cases (26.5%) received a dosage of 61 to 120 mg/d and those in 4 cases (5.9%) received a dosage of≥120 mg/d. The overall rate of relief from pain was 95.6%, among which the rates of excellent, effective and moderate relief were 39.7%, 48.5% and 7.4%, respectively. Oxycodone had mild side effects and quality of life was markedly improved. Conclusions: Oxycodone is effective in treatment of moderate and severe cancer pain. The side effects of oxycodone are mild, and the drug can significantly improve the quality of life for patients with cancer pain.