Abstract: Objective: To study the process of 64-slices detectors CT examination in patients by the implement of Lean Six Sigma methods: In order to reduce the patients' invalid waiting time so as to raise the patient's flux.Methods Five-step method in Lean Six Sigma management system was performed and implemented.According to such segments as the time of registration,waiting for CT examination,CT examination,films printing,films collecting,CT image interpretation,taking diagnostic report,160 patients were randomly selected to analyze the times of each segment to find the key factor of resulting in extending the whole CT examination time.Refining methods to aim directly at the factors of resulting in the whole CT examination time were prolonged were proposed to improve the conventional CT examination process.And these methods were retained to be modified and optimized to increase the performed CT scan's patients in each segment.Then,another 160 patients were randomly selected to be compared with the fore 160 patients for the total time of CT examination after the refining methods were performed.Results: The average invalid waiting time of the patients were dropped from 88.50 min to 52.30 min with statistically difference(P<0.01).The Six Sigma value(Z value) was increased from —0.54 to 5.12.Conclusion: The implementing of Lean Six Sigma in the 64-slices CT examination process can shorten the patient's invalid waiting time significantly and improve the patient's flux of single 64-slices CT scanner in each work-day.