1955 年，毛澤東從批判胡風進而發動的「肅清暗藏反革命分子運動」，乃是中共制定頒布「五四憲法」和法院、檢察等重要組織法以後，首次推行的群眾運動。其來勢凶猛、波及者眾，更對中共初創的國家法制，造成嚴重衝擊和考驗。彭真在中央既與聞最高決策，也是具體分管政法工作的主要人士之一，同時也是中共首都北京市的領導人，他對「肅反」運動的推進、「典型」創造、激化、收場和事後辯護，多方面地深度參與。本文不僅重建彭真在「肅反」運動中的重要歷史角色和影響（其官方傳記對此欠缺討論），也突顯中共建政初年試圖發展法制、又戀棧群眾運動的內在矛盾和張力，亦反映中共早期領導人對法律的認識和觀念。

In 1955, Mao Zedong, the Chairman of the Chinese Communist Party (CCP), harshly criticized Hu Feng, and then launched the Campaign to eradicate hidden counterrevolutionaries (Sufan Movement). It was the first political campaign since the 1954 Constitution and the organic laws of courts and procuratorates were adopted and enacted in the People’s Republic of China (PRC). The campaign came fiercely and affected many people, causing serious damages and challenges to the newly-established national legal system of the PRC. As an important central leader who participated at the decisionmaking and simultaneously took charge of the political-legal works, and concurrently leading nation’s capital-the Beijing Municipality, Peng Zhen was deeply involved in the many dimensions of the Sufan Movement such as facilitating and radicalizing the campaign, and creating the model experience. The article not only carefully examines and rebuilds the important historical role played by Peng Zhen in the Sufan Movement (his official biography was lacking discussion of this issue), but also highlights the internal contradiction and tension of aiming at the developing law system and continuing obsession with the mass movement in the initial years after the founding of the PRC. The article also reflects on the understanding and perception of law of the early CCP leaders.