Abstract: Helical tomotherapy (HT), as a new IMRT technology, utilizes a fan beam of radiation for treatment. It combines the main characteristics of a modern CT scanner and a linear accelerator to achieve the function of helical tomotherapy. Due to the complexity of the system with a highly integrated and automated features, monitoring its operation, continuing to improve the stability and reliability, and simplifying its quality control procedures has become an important part of quality assurance (QA) for HT. Based on the results of a five-year quality control (QC) program, and the initial application of new QA equipment, this study will summarize the standardization mode of its QA and explore the changes of QA mode.