Abstract: Because the Japanese economy was unable like the expectation such to resume former days's growth throughout, depended upon the tax revenue growth to melt the financial risk the desire to fail unceasingly, the Japanese government started from the 1980s the financial reconstruction hope to repose in the public disbursement compression, but the fact proved that Japan's public disbursement expanded is unable to be under the control throughout, presented the strong rigid This article embarks from the Japanese finance decision-making's political process, the utilization public choice theory, to causes the Japanese public disbursement rigid political factor to carry on the analysis, thought that the financial reform involves various political main body interest relations the adjustment, and reflects through the political procedure; Simultaneously Japan in the economy surpasses the policy decision tree which in the process forms, will cause Japan to encounter the bigger political hindrance in the compression public disbursement process