在醫療糾紛的案件中，事實認定的爭議部份則由陪審團或法官(在無陪審團之情況下)在案件審理中，藉由雙方舉證責任分配的過程依雙方所提出的證據加以決定。因此在原告滿足其案件繫屬的初始舉證責任後，雙方舉證責任的分配便依法規範加以實踐。在一般民事訴訟的案件中，原告負有舉證的責任，但是在醫療糾紛民事案件舉證的標準上，可能出現訴訟過程中舉證責任倒置的情況，而本文的重點即在探討美國在醫療糾紛民事案件中的舉證責任分配。因此本文首先擬就美國一般民事案件訴訟過程中的舉證責任原則加以簡要說明，其次針對美國對於醫療過失案件訴訟過程中所採取舉證責任倒置(res ipsa loquitur)的想法與內容加以說明，最後再以最近美國的相關案例說明，藉此對於美國目前關於醫療過失民事案件訴訟過程中舉證責任倒置的趨勢現況提出個人的觀察與建議。

In medical malpractice cases, factual issues are decided by a fact finder (either a jury or trial judge) through evidence provided by both parties in the process of deciding the burden of proof. After the plaintiff satisfies the prima facie case requirements, allocation of the burden of proof in a trial follows according to the rule of law. In ordinary situations, a plaintiff has the ultimate burden of persuasion in a trial, but with trials of medical malpractice, sometimes the rules for allocating the burden of proof differ under some circumstances. The issue of allocating the burden of proof in trials of medical malpractice cases is the focus of this article. Based upon the introductory material and for the purpose of this article, in the beginning, this paper provides a brief explanation of the general principle of allocation of the burden of proof in a trial of civil litigation in the US. Then, the idea and substantial content of the res ipsa loquitur principle related to trials of medical malpractice for allocation of the burden of proof in the US are introduced. In the last part of this article, a fairly recent case related to the res ipsa loquitur principle is discussed, and personal observations of future trends in dealingwith the issue of allocating the burden of proof in medicalmalpractice litigation are made.