The purpose of this research is to examine the effect of good corporate governance on firm value with the financial performance as the mediating variable. Secondary data is used data that published on state-owned enterprises company listed in Indonesia Stock Exchange from 2012-2018. Sampling technique used were purposive sampling. There were 89 state-owned enterprises companies listed in 2012-2018 periods. Hypothesis testing is done by using regression analysis model contained in STATA 14. The results of this study showed: 1) financial performance did not mediate the effect of size of board director and firm value. 2) financial performance did not mediate the effect of size of the audit committee and firm value. 3) financial performance mediate the effect of size of independent commissioners and firm value.