Objective To investigate the combination of Oxycodone and Morphine Hydrochloride Injec-tion in cancer pain and breakthrough cancer pain (BtCP).Methods This study included 78 patients with moder-ate or severe cancer pain ,which was titration with Oxycodone and Morphine Hydrochloride Injection .All data were obtained from diagnosed malignant tumors and followed up in the people ′s hospital of Jiangmen city between Jan 2011 and Dec 2015.Results The first 5 days of the titration with a total Morphine Equivalent Dose (MED)be-tween 156~1 491 mg(426.46 ±286.00 mg),and a total dose of IV morphine hydrochloride injection between 2~57 mg(20.96 ±13.25 mg).The mean dose used in the treatment of BtCP was 2.23 ±2.50 mg in Phase B(8 pm~8 am)and 1.96 ±2.14 mg in Phase A(P<0.05).When the treatment begun Numerical Rating Scale (NRS)showed a significant decrease .All the patients were less likely to experience any severe side -effects. Conclusion The titration by Oxycodone and Morphine Hydrochloride Injection is a simple , safe and efficient method,with less side-effect,significantly improve the living quality .It′s a good choice in the titration of moder-ate or severe cancer pain .