Background: In China, the prevalence of superficial fungal infections of the foot is high and recurrence is common. However, a prospective, large-scale and multicentre study on the aetiology of superficial fungal infections of the foot is still lacking. Objectives: To study the epidemiology of aetiological agents of superficial fungal infections of the foot in urban outpatients in mainland China, as well as to understand the aetiology features of the pathogenic agent. Methods: The study was designed as a multicentre, prospective epidemiological survey. A total of 1704 subjects were enrolled from seven geographical areas in mainland China. For each subject, one mycological sample and one bacterial sample were collected. KOH wet mount examination and culture were performed at local laboratories. The bacterial results were only reported in those with positive mycology. Further morphological identification and, if necessary, molecular biological identification were conducted in a central laboratory. Results: Of 1704 enrolled subjects, 1327 (77.9%) subjects had positive fungal culture results. The incidence of dermatophytes, yeasts and moulds was 90.1%, 8.1% and 1.1%, respectively. The most frequently isolated aetiological agent (fungus) was Superficial fungal infection of the foot is a common infectious skin disease, which is widespread in the world. The most common pathogenic agent of superficial fungal infections of the foot are dermatophytes, while moulds and yeasts are relatively rare. China has a vast territory and a huge population (1395 million in 2018). The climate and living habits vary across different regions. In the past 30 years, China's economy has developed rapidly, urbanisation has accelerated, and people's social habits have changed. All of this has an impact on the distribution of superficial fungi, which are widespread and inter-transmitted in the population. Nationwide epidemiological studies on superficial fungal infections of the foot are rare. 1,2 This study covers all areas in mainland China, prospectively investigating the pathogenic fungal species of superficial fungal infections in the foot, and further studied the correlation between different clinical types and pathogenic fungi as well as bacterial isolations that co-exist with fungal infection, and a questionnaire survey was conducted to understand the characteristics of people with superficial fungal infections in the foot.