Abstract: The determination of infringement of the adaptation right is a challenging issue in copyright law. This challenge is characterized by ambiguities in the scope of protection for the adaptation right. Additionally, there is insufficient attention to the identification of the source relationship of adaptation and a lack of unified methods and standards for determining substantial similarity. Judicial determinations and theoretical research on the scope of protection for the adaptation right remain relatively weak. Courts have failed to accurately grasp the independent value of the access element. Moreover, there is a lack of the evidential similarity criterion for determination in China. Additionally, the criteria for originality are vague, and the boundary between ideas and expressions remains unclear. Based on these issues, it is recommended to adopt a dual behavior-work interpretive approach. This approach should be supplemented by the potential market to assist in defining the scope of protection for the adaptation right. It is also necessary to strengthen the independent recognition status of the access element and introduce evidential similarity. Moreover, the relevant audience criterion for determination should be adopted to refine the process of determining substantial similarity. Specifically, the total concept and feel test and the abstraction-filtration-comparison test method should be comprehensively utilized as core determination tools.