Abstract: OBJECTIVE To evaluate cost-effectiveness of the strong opioid drug oxycodone and the weak opioid drug tramadol for treatment of moderate cancer pain patients by decision tree model. METHODS A meta-analysis of related randomised controlled clinical trials that were retrieved in medical databases to obtain effective rate and adverse effects rate. Cost-effectiveness analysis was performed with decision tree model that was created by treeage software. RESULTS In contrast with tramadol, incremental cost-effectiveness ratio (ICER) of oxycodone group was RMB 458.89 every person. Sensitivity analysis showed that the results were stablely. CONCLUSION ICER<3 times GDP per capita, the cost of oxycodone treatment is acceptable. In contrast, cost effectiveness of oxycodone is more than tramadol for treating moderate cancer pain in Chinese population.