The International Baccalaureate Organization (IBO) has recently implemented a series of curriculum changes in its Diploma Program (IBDP). Among these, teachers are concerned with the requirements of concept-driven curriculum. For second language courses, the concepts, including "audience, context and purpose", are important ideas in language acquisition theories. This paper provides the relevant theories, and presents feasible teaching steps for curriculum design that were elicited from the experiences of a few Hong Kong international schools. From teachers' and students' reflection and observation, we have found that concept-driven curriculum can effectively help students organise discrete knowledge, improve students' thinking skills, and allow the transfer and application of knowledge to new situations.