This paper analyzes the laws and regulations related to marathon sports，and analyzes the potential legal risks of marathon sports events. Marathon-related legal system includes marathon-related laws，regulations，rules，normative documents and so on. This paper not only analyzes the relevant laws of marathon，but also studies the relevant regulations of Chinese Athletics Association for marathon sports. This paper analyzes the conditions of marathon event hosting and takes the 2021 Marathon Championship as an example. This paper analyzes the rating methods of marathon events and the relevant regulations of sponsors in marathon events. Through the analysis of legal cases of marathon events，this paper analyzes the tort liability and exclusive rights in marathon，so as to help sponsors，organizers and other relevant departments to avoid legal risks of the events.