In this globalization era, every single company have to be more competitive on how the company can work together along with all departements in order to achieve the goal of the company and in the same time the role of Board of Director is very much important who become an executor for all decision making. However, In the very beginning researher detect and analyze board of director are sometimes many on board of SOEs, while in the same time they don‟t really work properly and the salary is automatically expensive. From that information, researcher try to conduct a research by using state owned enterprises to analyze and detect the relationship about existing board of director size to return on asset, return on equity, profit margin, as well as earning per share, listed in Indonesia Stock Exchange the last five years. It is because, In the previous research under the title “The Relationship Between Board Characteristic And Firm Performance in Malaysia” and one of independent variable was that board size has a significantimpact to dependent variable such as ROA (Return On Asset) and ROE (Return On Equity).From that previous research, researcher has an inspiration to conduct such that research about the relationship of board size on financial performance since nobody has never done to conduct in state owned enterprises listed in Indonesia Stock Exchange.This research uses board of director size as independent variable, and return on asset (ROA), return on equity (ROE), profit margin (PM), as well as earning per share (EPS) as dependent variable. Then, the data is coming from IDX‟s website,and lireature review such as books, as well as SPSS 2.0 version is the analysis tool that researcher used in this thesis.Then, it is found that state owned enterprises (SOE) specificaly board of director size has a weak relationship to return on asset, and return on equity. Then, board of director size has a strong relationship to profit margin and earning per share.State owned enterprises (SOE) must be more concerning about how to improve the return on asset as well as return on equity for the company due to strengthen the company in the long run. Therefore, state owned enterprises (SOE) can use this research as reference to detect the problem in the deep side.Thus, researcher recommend that state owned enterprises to concern the return on asset and return on equity to strenghten in the long run for state owned enterprise (SOE). While, in the next future study the data should be larger to really see the pattern of the trend over ten years or more and it would more trust worthly to formulate the strategy.