The discipline of public administration has undergone constant change in its long journey in history. The recent change in the discipline that still carries the traces of the change in its early stages began with the politics-administration dichotomy with the contribution of Wilson and Goodnow in the United States. Then came the era of "the principles of public administration" with the contribution of Willoughby and White. The U.S. practices that shaped the discipline of public administration led to the emergence of orthodox public administration in the United States in the period between the World War I and World War II. These wars brought about downsizing of public administration and search for savings and efficiency measures particularly in the United States. After the war, challenges were faced concerning the problems of public administration. In that process, Dwight Waldo, who criticized orthodox public administration, and thus, was engaged in search of new ideas in the discipline of public administration, laid the intellectual infrastructure of the notion of new public management founded on the effectiveness and efficiency of the public administration with his new ideas. This study will scrutinize in detail Waldo's ideas, and will discuss his contributions to the process of change in the discipline of public administration.