There are two approaches to research synthesis: systematic review and meta-analysis. Meta-analysis is a set of statistical methods for combing quantitative results from multiple studies to produce an overall summary of empirical knowledge on a given topic. The author presents the functions of meta-analysis, and interprets the meanings of the results of meta-analysis, such as effect sizes, heterogeneity, forest plots, and funnel plots. Finally, examples are used to describe the application of meta-analysis. This article may help long-term care professionals to read meta-analysis papers and then engage in conducting meta-analysis.