This article aims to identify important factors leading to integrity breaches in China's current public procurement and provides insights into ways to diminish them. It develops and tests a theoretical model of supplier integrity, which identifies three external factors (i.e. laws and regulations, supervision and government procurement centres) and one internal factor (i.e. organisational motivations) as antecedents of organisational qualities, which in turn govern organisational integrity. The model is tested using survey data. The results suggest that laws and regulations, and supervision do not have any significant effect on suppliers, but government procurement centres and organisational motivations have positively affected suppliers' organisational qualities, which reduce integrity breaches. This article thus recommends further unification reform on laws and regulations as well as supervision to control suppliers' integrity breaches.