The concept of "harmony" was taught by the Chinese sages as the practice of acceptance, tolerance, mutual respect, equality and patience, and is now given great importance by the Chinese government in its attempts to promote the stability and sustainability of the country. The concept could have significant implications for moral education. This article uses a Chinese Masters course on sustainability education as an example to analyse the positive and negative implications of the principle of harmony both for the practice of sustainability education and for educational practice in general. The course encouraged students to plan and implement feasible and practical sustainability activities mainly in the context of Chinese schools. Influenced by the value of harmony, the course chose to promote sustainability in a pragmatic but limited way. Although the course resulted in some practical sustainability related activities, a holistic and critical view on sustainability was not evident amongst the students. However, the principle of harmony could be applied critically both as a criterion for evaluating social development and as a value underlying democratic decision-making. (Contains 2 notes.)