More than three years have passed since Korean companies introduced Six-Sigma. Each company used a lot of quality improvement tools for years. However, the tools have been taught to the companies with a little understanding of Six sigma tools. Therefore, it is difficult to use the tools correctly at appropriate time. This survey paper was conducted on MBBs and BBs of the manufacturing companies that introduced Six-Sigma. It is intended, in this paper, to provide the companies that will be introduce Six-Sigma a guideline of training course and tools by understanding the importance of each DMAIC stage of Six-Sigma, examining the frequently used tools in each process and their performances, and selecting the key tools for each stage based on the result of this survey.