This paper argues that Japanese interest group politics is now in transition, as the power of interest groups are declining, while the power of the executive branch is increasing. A substantial part of this change can be explained by the institutional changes, such as election system reform and administrative reform. However, we show it is before these institutional changes that various political actors changed their normative evaluation of interest groups politics. In order to make sense of this change, it seems to be necessary to analyze political dynamics at the deeper level than the strategic choice of the political actors.