<p>What causes school bullying? Inspired by Prieur’s contribution to “a criminology of structurally conditioned emotions,” this article integrates general strain theory and edgework theory, perceiving emotions as a link between strains and deviant behaviors in the study of school bullying. Based on semi-structured interviews with 34 participants including students, experienced education professionals and legal practitioners in an inland Chinese city, it examines the major categories of strains that students encounter in their families and schools, resulting in structurally conditioned emotions. Meanwhile, it explores the role of individuals’ agency in motivating students to regulate their negative emotional states, through strategies including alleviating negative emotions and pursuing emotional rewards. Bullying then emerges as their adaptive strategy. This article applies this integrated theoretical framework to examine the causes of school bullying, a prevalent form of deviant behavior exhibited by strained students. It offers one of the first qualitative studies on school bullying in the Chinese context.</p>