Objective:To compare the efficacy of individualized herbal decoction with Bronchiectasis Stabilization Decoction within a patient with stable bronchiectasis through N-of-1 RCT (Single case randomized controlled trial). MethodsThe lengths of observation period and washout period of a patient with stable bronchiectasis were determined by preliminary test, and then We conducted N-of-1 RCT (single-patient, double-blind, randomized, multiple crossover design) with 3cycles in 1 patient with stable bronchiectasis. The primary outcome was patient self-reported symptom scores on a visual analogue scale (VAS), 24-hour sputum volume and CAT (The COPD Assessment Test) scores were observed.  Results:①After three rounds of trial, the symptom scores of the trial periods diminished significantly more than control periods (P<0.05),and the lower limit of the 95% confidence interval of the mean change was 1.53 (>0.5), indicating that the individualized herbal decoction has clinical superiority over the controlled decoction. ②After three rounds of trial, 24-hour sputum volume of the trial periods diminished significantly more than control periods (P<0.05). ③After three rounds of trial, the scores of CAT scale of the trial periods diminished significantly more than control periods (P<0.05),indicating better quality of life in the trial periods.  Conclusion:N-of-1 RCT reflected the advantage of TCM individualized treatment in this patient with stable bronchiectasis, it also provided with the highest rank of evidence of evidence-based medicine for this patient.