Abstract: Objective To evaluate the efficacy and safety of oxycodone hydrochloride sustainedrelease tablets and immediate-release morphine tablets in the titration of patients with moderate or severe cancer pain. Methods China national knowledge infrastructure(CNKI) fulltext database， Chinese science and technology journal fulltext database （VIP） and digital journal full-text database of Wanfang were searched. Oxycodone hydrochloride sustained-release tablets and immediate-release morphine tablets were included into the prospective randomized controlled trial （RCT） of moderate to severe cancer pain titration. Methodological assessment of bias risk of the included studies has been performed. The meta analysis of the included studies has been carried out. Results According to the inclusion criteria， 12 RCTs involving 1131 patients were included and subgroup analysis were performed. Meta-analysis results showed that： （1） As for the 1 h pain relief rate， oxycodone hydrochloride sustained-release tablets was significantly better than immediaterelease morphine tablets（RR=3.16， 95％CI：1.64-6.08， P=0.0006）； （2） As for the 4 h pain relief rate， oxycodone hydrochloride sustained-release tablets was significantly better than immediate-release morphine tablets（RR=2.44， 95％CI：1.49-3.97， P=0.0004）； （3） As for the 24 h pain relief rate， oxycodone hydrochloride sustained-release tablets was significantly better than immediaterelease morphine tablets（RR=1.13， 95％CI：1.04-1.24， P=0.005）； （4） As for the titration cycles， oxycodone hydrochloride sustainedrelease tablets was significantly shorter than immediaterelease morphine tablets （MD=-0.77， 95％CI：-1.14--0.40， P＜0.0001）； （5） As for the time to onset， oxycodone hydrochloride sustained-release tablets was significantly faster than immediaterelease morphine tablets （MD=-29.63， 95％CI：-45.54--13.73， P=0.0003）；（6） In terms of adverse reactions， the incidence of constipation（RR=0.69, 95%CI: 0.52-0.92, P=0.01）， nausea and vomiting（RR=0.57, 95%CI: 0.45-0.73, P＜0.000 01） of oxycodone hydrochloride sustained-release tablets were significantly lower than immediate-release morphine tablets； There was no significant difference in the comparison of other adverse reactions（P＞0.05）. ConclusionOxycodone hydrochloride sustained-release tablets has significantly higher 1 h， 4 h and 24 h pain relief rates than immediate-release morphine tablets so that the titration can be completed faster. And it also has significantly shorter titration cycles and the time to onset. Oxycodone sustained-release tablets performs better than immediate-release morphine tablets in the treatment of moderate and severe cancer pain， and leads to less incidences of constipation， nausea and vomiting. Consequently， it will be a better medication choice for moderate or severe cancer pain titration.