美国作为世界最发达国家，其司法体制的健全完善也是有目共睹。尽管美国保留死刑制度的做法与西方国家废除死刑的主流思想相悖，但是其对待死刑的态度是限制且慎重的。由于美国的司法制度高度重视人权保障与法律公正，因此联邦法律和很多州的法律都对死刑进行了具体细致的规定。为了最大程度的维护死刑程序的正当合法，美国联邦和保留死刑的各州法律都对死刑提供了广泛的救济渠道，主要包括宪法的人身保护令以及上诉复审等渠道。而新证据的提出作为刑事再审的重要事由之一，既要尊重生效裁判的效力，保证司法程序正当，又要使原审的错误裁判得到纠正，使原案当事人的权利得到救济。因此新证据理论就特别值得深入分析和研究。本文旨在通过对1992年埃雷拉诉柯林斯（Herrera v. Collins）案的分析，对新证据理论进行深入的探讨和研究。被告人埃雷拉在1981被控谋杀两名警察并被地区法院判处死刑，自此以后埃雷拉走上了漫长的诉讼道路，埃雷拉在提请联邦法院对其给予人身保护令的同时提交了新的无罪证据，但该证据并没有被采纳，最终埃雷拉被执行了死刑。该案件在全美引起了强烈反响，美国政府对该案的简报中写到：“宪法赋予囚犯寻求对新发现的证据主张进行司法评判的权利，难道不是被要求在量刑过程中寻求宽大处理吗？”申请人埃雷拉（Leonel Torres Herrer）于1982年1月被法院判决谋杀罪名成立并对其判处死刑。他在德克萨斯州法院对有罪判决的直接上诉、国家担保诉讼以及对人身保护令的申请均未成功。在1992年2月也就是他被判有罪的十年以后，他再次提出了联邦人身保护令的申请。他声称，尽管被判处死刑，但实际上他是无辜的，基于宪法第八修正案和第十四修正案“残酷和不寻常的”条款应当禁止对其执行死刑。值得我们思考的是怎样的新证据可以成为申请再审或其它救济的事由，新证据本身又应当具备怎样的效力。本文第一部分从埃雷拉案件的背景，事实，审理以及相关法律问题入手，使读者对案件有初步的认识，再根据案件的判决总结出该案的争议焦点。第二部分对新证据进行理论上的剖析，介绍新证据的概念、特点以及其证明力问题，使读者对新证据理论有系统的认知。接下来通过对新证据争议的讨论引发对新证据效力在不同理论基础上的分析，即从分析实证主义和自然法学派两种法学理念分析新证据。第四部通过对该案分析，结合我国司法的实际情况，分析新证据理论在我国实践中存在的问题并提出解决意见。

As the most developed country in world, America has a sound judicial system. America maintains capital punishment which is different from the mainstream of western countries’ opinion of abolishing capital punishment, but America imposes very stringent restrictive regulations on the use of this extreme measure. America judicial system pays close attention to Human Rights and justice, so federal law and many state laws stipulate in detail of capital punishment. In order to make a proper procedure of capital punishment the U.S. federal government and states maintain capital punishment provide subsidies through various channels. Include The Privilege of the Writ of Habeas Corpus and review on appeal. New Evidence as the important fact of the current retry procedure, on one hand it respects the legally effective judgment ,on the other hand when application of law in the original judgment or ruling is found to be erroneous, it reinforces the relief function. So New Evidence requires thoroughly study.The article focuses on analysis of Herrera v. Collins, in order to study the New Evidence Theory. Herrera v. Collins have be accused of murdering two policemen in 1981 and sentenced to death, from then on Herrera v. Collins has instituted legal proceedings for a long time. As well as asked for Habeas Corpus, he also brought forth convincing evidence to clear himself, but the evidence was not accepted and Herrera v. Collins was finally executed. This case caused a strong reaction in the whole U.S.A.The first section of this paper focus on Herrera v. Collins Case’s background, facts, and the legal problems, provided a general outline of this case and concludes the disputes. The second section of this paper analyzed theoretically about New Evidence’s concept, characteristics and competency of it’s evidence, in order to promote awareness and understanding of New Evidence. From the law-of-nature school and Analytical-positivist jurisprudence two ways this paper analyzed availability of New Evidence in practice. The fourth section of this paper based on the real situation in China judicial circumstance, analyzed the present situation and problem of the New Evidence and gives advice to overcome any potentially critical problems.