Breaches of the psychological contract (i.e., subjective experiences that are based on an individual's perception that another party has failed to realise the obligations that had been promised) can have negative consequences for employees, such as reducing employees' performance, job satisfaction and organisational commitment. The main aim of this study is to examine how employee attributions about the causes of psychological contract breach shape the relationship between psychological contract breach and employee outcomes. Based on existing literatures, two models concerning of the role of employee attributions are compared. A moderation model proposes that employee attributions moderate the relationship between psychological contract breach and employees outcomes. A mediation model asserts that employee attributions play a mediating role in the mechanism of psychological contract breach affecting employee outcomes. In addition, a relatively unexplored aspect why employees make different attributions in response to psychological contract breach was identified. The aim of this study is to examine whether individual differences (i.e., individualism/collectivism and employee proactivity) shape the employee attributions of psychological contract breach. Two survey-based studies were conducted in China. The first study (N = 261) developed new measures of psychological contract breach and employee attributions. The second study (N = 634) further refined the new measures and tested the study hypotheses using Structural Equation Modelling. The results show that psychological contract breach was significantly related to internal and external employee attributions as well as employee outcomes (i.e., employee well-being, leadership perceptions and supervisor ratings of performance). But a central message that emerges from this research is that employee attributions are more likely to play a moderating role than a mediating role in the relationship between psychological contract breach and employee outcomes. This study mainly has four theoretical contributions, which are developing and testing a model of psychological contract breach and employee attributions, extending the understanding of the relationship between psychological contract breach and employee attributions, extending the criterion space of psychological contract breach and employee attributions, and developing a more specific understanding of how employee attributions shape the employee outcomes of psychological contract breach.