This article examines how “human affect” (renqing) – the interplay of affect, moral obligation and social legitimacy – operates as both a mechanism of governance and a site of contestation in police mediation in contemporary China. Drawing on six months of ethnographic fieldwork in two police stations in Zhejiang province, I conceptualize renqing as an affective grammar: a system of emotional expression and recognition that structures interaction across interpersonal and institutional settings. The party-state’s revival of the Fengqiao model has transformed renqing from a micro-political norm into an institutionalized instrument of affective governance. Mediation formalizes affect through contracts, scripted performances and service quotas, stratifying emotional legitimacy along lines of class, gender and migration. The article theorizes affective autonomy as participants’ resistance through silence, withdrawal or alternative alignments. It complicates portrayals of policing as purely coercive, highlighting the emotional labour and limits of grassroots governance.