Values education is important in the General Studies curriculum of Hong Kong. Emphasis has been placed on pupils' affective development including strengthening elements related to making good use of resources and environmental conservation. Teachers are presumed to be able to transform subject disciplinary knowledge into forms that are comprehensible to their pupils. In dealing with values-based topics in the General Studies curriculum, however, teachers often assume that their ways of seeing the content is the same as those of their pupils and tend to prescribe what pupils should or should not do without developing with them a clear rationale. In Learning Study, teacher professional learning is closely interwoven with pupil learning. It uses an action research methodology which is grounded in the Theory of Variation. This paper presents a Learning Study of six General Studies teachers who worked together to develop a series of research lessons on "Saving electricity" at Primary 3 level in Hong Kong. A particular focus will be placed on examining teachers' professional development through engaging in professional dialogue and working in cycles in their research lessons to improve teaching and learning in dealing with this value-based topic.