Abstract: As a powerful tool for continuous improvement and innovation, Lean Six Sigma (LSS) has been widely used in industries including manufacturing, construction, service and even non-profit organizations. But there are some discrepancies about the understanding of LSS for both academicians and practitioners. To have a sound understanding of LSS, based on the reviews of 2701 papers from Web of Science with “Six Sigma” or “Lean Six Sigma” in titles, the evolution of LSS and a big picture about LSS research and application are presented. Six main research topics are discussed. The development trend of LSS from the perspectives of strategy, system and integration are predicted so as to provide some guidance and references for future LSS academic research and application.