This research tried to analyze substitution relationship among debt policy, dividend and insider ownershipstructure as the agency control mechanism on manufacturing firms in period 2005-2009. The hypothesisproposed in this paper were there was a substitution relationship between insider’s ownership and debt policyin reducing agency conflict, there was a substitution relationship between debt and dividend policy in reducingagency conflict and there was substitution relationship between insider’s ownership and dividend policyin reducing agency conflict. This research used purposive sampling method to determine samples and therewere 42 firms as the samples. The analysis instrument used was simultaneous equation model by using twostages least square method. These empirical results verified that debt and dividend policy was determined bysimultaneous, while insider ownership did not influence debt policy. Hypothesis test showed that there was nosubstitution relationship between insider’s ownership and debt policy in reducing agency conflict, there wassubstitution relationship between debt and dividend policy in reducing agency conflict and there was substitutionrelationship between insider’s ownership and dividend policy in reducing agency conflict. Because as awhole, eventhough not fully, there was simultaneity among debt policy, insider’s ownership and dividend itwas expected to increase firm value.