The core status of documentary evidence in civil litigation in China makes the authenticity of documents almost the most crucial issue during the trial of many civil cases. The strength of documentary evidence could often decide the final results of the disputed case before court. And if challenging the authenticity of decisive documentary evidence is successful, such a move is more likely to have a miraculous effect. Within the process of legal argument and fact-finding, a document may become the direct evidence of some legal elements or essential factual allegations, which leads to the determination of substantive results of the current case, and may also become the basis for determining the existence of a specific substantive legal relationship (such as a will or a contract). When the issue of authenticity is in dispute and needs to be submitted to the court for determination, the related procedures are complex and diversified. In a broader sense, the authenticity of documentary evidence includes the authenticity of documentary evidence itself (whether the documentary evidence is real and not counterfeit) and its function of proving the facts (the probative force (Beweiskraft) of the documentary evidence). There are obvious differences between the approaches of the common law and continental law. following the basic judgment logic from the subject matter of claims to the facts and then to the proof with evidence, this chapter first focuses on the independent claim for declaration filed against the authenticity of documents under the laws of Germany, Japan and China Taiwan within civil law systems. Then, it turns to propose that China shall, on the basis of inheriting and developing such comparative experience, endeavor to consider the authenticity of relevant documents as a disputed issue of evidence in the ordinary civil proceedings, and construct its procedural mechanism from three aspects, namely, the formal requirements, the allocation of burden of proof as well as the practical means to determine the authenticity. After discussing the meaning of the concept of formal probative force and the relationship between the concepts of the authenticity of documentary evidence and formal probative force, this chapter establishes the presumption rule of formal probative force of documentary evidence based on the interpretation of current Chinese law. In addition, although within the system of probative force of documentary evidence under civil law systems, the issue of authenticity of documentary evidence and the issue of substantial probative force of documentary evidence always appear simultaneously, this chapter is to focus on the authenticity of documentary evidence itself. As for most types of evidence, the issue of substantial probative force is decided by the decision-makers during their free evaluation.