Treatment based on syndrome differentiation is the essence of traditional Chinese Medicine(TCM) and forms the individualized treatment. N-of-1 trials may be a good clinical effect evaluation method for the individualized treatment of TCM. This study aims to compare: (1) the efficacy of syndrome differentiation(individualized decoction) with placebo, (2)the efficacy of syndrome differentiation(individualized decoction) with the same prescription minus heat-clearing Chinese herbs, for patients with stable bronchiectasis through N-of-1 trials.