This research aims to analyze and obtain the empirical study about the effect of Loan to Deposit Ratio (LDR), Non Performing Loan (NPL) and Net Interest Margin (NIM) to Return on Assets (ROA) and the moderating effect of Efficiency (OEOI) on the variable that affect Return on Assets (ROA). The data population is 43 banking companies listed in Indonesia stock exchange and published its financial statements during the period 2012 to 2016. However, there are only 30 companies met the criteria as samples. This study found that NIM, NPL and OEOI affecting ROA. While other factors such as LDR has no effect on ROA. The study also found that OEOI has a partial mediation between the influence of NIM and ROA. The study also proves that ROA is influenced by variable observed by 48, 7%. It also can be concluded that the other factor over the observe independent variable that effect ROA is 51,3%.