In Hong Kong and Canada, indeed globally, slogans about learning to learn and teaching for 21st-century knowledge and skills are common. However, there are few examples of how teacher education courses or programs are responding to these new demands. In this paper, we propose a framework for designing teacher education premised on the theoretical perspective of knowledge building. We describe two courses, a pre-service teacher education in course Hong Kong teachers and a joint graduate course for Hong Kong and Canadian teachers. In both cases, participants engaged in knowledge-building discourse mediated by a computer-supported learning environment. We present the design and illustrate how the teachers were able to work as collaborative inquirers and knowledge creators in a knowledge-building community. Implications of knowledge building for teacher development as related to socio-cultural contexts are discussed.