Adopting a lens of unintended policy consequences, this article attempts to explore the paradoxical phenomena New Public Management (NPM) Reform has produced over nearly three decades. These paradoxical phenomena represent contradicting value and goals which public policy system should satisfy simultaneously, and also indicate that public policy planning and implantation often give rise to unintended consequences. This article will try to combine Robert K. Merton’s perspective of "unanticipated consequences of purposive action" and a historical institutionalist approach to public management policy change to explore the possible causal explanations of theses paradoxical phenomena. In this way, it will help to enhance profound understanding of the deep structures and hidden value conflicts in public management policy system.