BACKGROUND: Chronic lung diseases, including bronchial asthma, chronic obstructive pulmonary disease (COPD),chronic bronchitis, allergic rhinitis and repeated respiratory tract infection (RRTL) in infants, exacerbate frequently in winter because of respiratory viral infections and low temperature. Summer acupoint application therapy (SAAT) is thought to be effective in reducing exacerbation frequency of chronic lung diseases in winter. It is a kind of therapy using a herbal mixture for external application on special acupoints during summer. The herbal mixture basically contains Semen Sinapis Albae, Herba Asari,Radix Euphorbiae Kansui and Rhizoma Cory dal is. The acupoints include Feishu (BL13), Dazhui (GV14) and Danzhong (CV17). Through a large-scale multicenter trial based on three years of clinical observation, and retrospective and prospective analyses, this study aims to explore the efficacy of SAAT.METHODS AND DESIGN: In this clinical observation trial, patients who have been diagnosed with bronchial asthma,COPD,chronic bronchitis, allergic rhinitis or RRTL will be enrolled from 13 centers. All patients enrolled will be treated with SAAT over a two-year period by medical practitioners. After this, an initial case report form (CRF) will be completed and forwarded to the central study site (China Academy of Chinese Medical Sciences, Beijing, China). The CRF is designed to investigate patients’ history of medical treatment (including SAAT) and chronic lung disease exacerbation, also self-reported health condition. For retrospective analyses, the authors will focus on those who have accepted SAAT before enrollment and will collect their SAAT history and chronic lung disease exacerbation history, to evaluate the effects of SAAT. For prospective analyses, medical students will follow up with patients by phone interviews in winter once a year. The primary outcome is frequency of chronic lung disease exacerbation in winter. The secondary outcomes include conditions of lung disease recovery, non-SAAT therapy, and a self health report.DISCUSSION: The authors aim to collect 7 400 patients from July 2008 to August 2009. The final follow-up has been completed in December 2010. To reduce the selection bias, a total of 13 clinical centers from different areas of China have participated in this study. The results from this study will provide a high-quality evidence base for evaluating the efficacy of SAAT in reducing exacerbation frequency of chronic lung diseases in winter.TRIAL REGISTRATION NUMBER: This trial has been registered in Chinese Clinical Trial Registry (Identifier： ChiCTR-TNRC-10001292).