本文是利用社會麥當勞化及績效悖理概念，批判地反思近二十多年來新公共管理意識型態所驅動下的公共部門績效管理改革。本文特別針對政府執法部門引進商業式的績效管理所帶來的後果，突出公共部門運用績效管理技術所面臨的困境。透過利用已長期進行績效管理的台灣警政部門作為範例，本文指出一個維護治安的政府部門的行為如何因為績效管理而被扭曲。縱然政府領導者已辨識到問題的存在，但由於長期的扭曲，如此的績效管理問題已形成台灣警政機關根深柢固的文化，難以糾正。這應可作為其他剛引進績效管理的執法機關的國家引以為鑑。 This article uses the concepts of McDonaldization of society and the performance paradox to consider critically the public performance management reforms driven by the ideology of New Public Management in the past two decades and more. It focusses on the aftermath of the application of business-like performance management to the Taiwan government’s law enforcement agencies in order to highlight the dilemma of the application of performance management techniques to the public sector. Through the case study of the police agency in Taiwan which has been implementing performance management for a long time, this article shows how the behaviour of a government agency responsible for maintaining social order has been distorted as a result of the performance management reforms. Though government leaders have identified the problem, it has already been deeply embedded in the police agency and become part of its culture, hence it is difficult to overcome the problem now. This case study should be a good reference for those countries which have just introduced performance management to law enforcement agencies.