Abstract
Synonym teaching is one of the important and difficult tasks of English vocabulary teaching in senior high schools. Teachers in senior high schools face various difficulties during the synonym teaching process. This paper aims to present some effective teaching strategies to promote the synonym teaching to achieve fruitful results. The paper introduces the definition and classification of synonym so that teachers could have a thorough and comprehensive understanding of synonym. The teaching of synonym requires a pedagogic theory as a guide. The authors adopt social constructivism, advanced by Martin Williams and Robert L. Burden in 1997, to guide synonym teaching. Further, in the light of social constructivism, the authors propose teaching principles and strategies for classroom synonym teaching, which will be of great help for senior high school synonym teaching.