This article surveys the research and development of Engineered Cementitious Composites (ECC) over the last decade since its invention in the early 1990s.The importance of micromechanics in the materials design strategy is emphasized.Observations of unique characteristics of ECC based on a broad range of theoretical and experimental research are examined.The advantageous use of ECC in certain categories of structural,and repair and retrofit applications is reviewed.While reflecting on past advances,future challenges for continued development and deployment of ECC are noted.This article is based on a keynote address given at the International Workshop on Ductile Fiber Reinforced Cementitious Composites (DFRCC)-Applications and Evaluations,sponsored by the Japan Concrete Institute,and held in October 2002 at Takayama,Japan.