The aims of this research were to determine the effect of the free cash flow, managerial ownership, institutional ownership on debt policy where investment opportunity set as moderate variable, subject at manufacturing company registered on the Indonesia Stock Exchange. This research was classified as causative study. The population of this research was manufacturing company registered on the Stock Exchange in 2011 until 2014. Total sample were 26 companies. The data collected using purposive sampling method. Data analysis techniques was used as analysis double regression technique. The result show that free cash flow has positive effect on debt policy, managerial ownership has negative effect on debt policy, institusional ownership hasn’t effect on debt policy, investment opportunity set weakened the effect of free cash flow on debt policy, investment opportunity set hasn’t effect when moderated managerial ownership on debt policy, and investment opportunity set has no effect of institusional ownership on debt policy. Key words : free cash flow, managerial ownership, institusional ownership, investment opportunity set, debt policy