Within person trial is an efficient study design for randomized controlled trials which has been widely used in fields of dentistry, dermatology and ophthalmology. However, due to a series of inherent methodological difficulties, the design, conduct and reporting of within person trials usually requires additional methodological knowledge and considerations from researchers. To standardize and improve the reporting quality of these trials, the BMJ recently published the CONSORT statement extension for within person trials. The present article aimed to provide interpretation of this reporting guideline, and thereby promote its understanding and use among Chinese researchers.