Abstract: The method of proving not intentional based on the definition of intentional violation developed from the precedents of the Court of Arbitration for Sport, and its value is recognized by the 2021 World Anti-Doping Code. When using this method to establish that the violation was not intentional, an athlete can disprove intention without showing the origin of the prohibited substance and therefore reduce the sanction of ineligibility if the relevant evidence demonstrates that he neither doped to enhance competition performance or disregarded the potential risk of violation. Through reviewing the changes in the relevant articles of the World Anti-Doping Code and summarizing the main points in the representative cases of the Court of Arbitration for Sport, it is clear that this method is only applied in the exceptional cases which the exact source of the prohibited substance cannot be identified, and when the method is applied, the athlete is required to state the circumstances that would rebut the intentional presumption, and provide a reasonable explanation of the possible source of the prohibited substance, and adduce evidence to support his claims.Considering the food safety situation, both athletes and sports organizations should focus on specific changes in the way this new method of non-intentional proof is implemented from different perspectives in order to actively apply it in anti-doping practice.