Abstract: Studies of translation norms focus on the constraint of the dominant norm to translators and the compliance of translation behaviours. While norm conformity explains the stability of the translation system, non-typical and incompliant behaviours can shed light on the change and evolution of the system. This article concentrates on the multiplicity of translation norms and its influence on translation behaviours. The research questions are:when do norms come into conflicts? How do translators react to norm conflicts? How do their reactions contribute to the change and evolution of the system? The study presents four types of norm conflicts and three modes of translation behaviours with a special reference to Zhang Guruo's translation of Tess of the d'Urbervilles published in 1936. The case study shows that translators often create new options instead of simply choosing between existing ones when confronted with norm conflicts. The article concludes with a call for more research on the multiplicity of norms and the complexity of translation behaviours.