The interpretation and implementation of ideas about the internationalisation of curricula (IoC) are complicated and multi-faceted. The complex and diverse perspectives on IoC reflect two concepts: "internationalisation" and "curriculum". These concepts embody contrasting perspectives on issues, including the competition-type and cooperation-type approaches to internationalisation, as well as the product and process curriculum models. These two approaches or models tend to go hand in hand while in a state of tension. The aim of this paper is to promote a detailed understanding of IoC through forming a conceptual framework for IoC. This framework proposes four patterns of IoC by linking the two approaches and the two models, and is examined using case studies of two types of Japanese universities. Finally, two assumptions are made for future research and development in the practice of IoC beyond Japan.