犯罪要受到刑罰之制裁，犯罪嫌疑人願意坦承供述自己犯罪事實而自白，顯然違反人類自我保護之本能，因此很多的自白多在不得已之情況下所作；在證據方法及價值上，自白仍具有為證據之王的地位，但不可否認的是：自白因其取得之程序往往涉及高度強制之色彩，而其有危險性及虛偽之不可避免性，共犯之自白更牽涉到栽贓、誣陷他人以脫免自己罪責之高度可能性；可見被告自白或共犯自白在刑事訴訟上有關證據法上之問題及癥結上，即在二處：一是自白任意性問題，二是自白真實性問題；從而，以自白作為供述證據，在法院審理時調查證據之程序應包含：一、是必須先就被告自白是否出於被告之任意性為調查，此是自白取得證據能力之基礎，凡非出於任意性的自由意志下所為之自白，即排除其做為證據能力而加以使用。二、是被告白白是否具有「審判上之其實性」，該白白是否與事實相符，乃白白真實性擔保問題，此是白白之證明力問題。 　　自白作為供述證據而採為判決所認定犯罪事實之基礎，以須具有「自白之任意性及真實性」；虛偽之自白供述，自無採為對待證之犯罪事實具有證據價值上之證明力。在自白任意性問題即自白取得合法性與否問題上，受到實務與學說大部分的關注，但在數人共犯一罪之共犯案件中，或共同被告案件中，共犯或共同被告一人之自白，所為之自白除自白自己犯罪部分外，更有供述其他人共同犯罪情形下之共犯自白或共同被告自白，共犯或共同被告一人之自白真實性擔保，則有很大之癥結與問題，在現行實務及學說上，均大抵要求以補強證據，補強自白在認定犯罪事實之真實性，但此是否即可確認該自白之真實呢？此乃共犯或共同被告自白真實性如何？本文認為除了以補強證據為擔保外，另應使被告在訴訟上對共犯白白證據之調查程序上，以對質詰問程序之進行，共同確保共犯所為自白憑信性之確認，此不僅具有深化被告訴訟主體地位及正當程序之要求，也是確保被告享有憲法保障公平審判權利。

　　Crime must be punished. When a suspect voluntarily confessed self-incriminating facts, it is obviously against self-protective human nature. Therefore, many confessions were made under circumstances where there is no free will exist. In terms of methodology and the weight of evidence, a confession still holds its paramount position among the evidences proffered. However, it is an undeniable fact that, due to its highly compulsory nature, inevitably the use of a confession is dangerous and fallible. Furthermore, an accomplice's confession might involve high possibility of implicating or framing up others for self-exculpation. Consequently, there are two critical evidentiary issues for using the confession of a suspect or his accomplices in a criminal process: 1. the voluntariness issue; 2. the truthfulness issue. Therefore, when a court is using testimonies of confession in its evidentiary investigation process, it should inquire that: 1. Whether the confession was made under free will ? Voluntariness is an evidentiary foundation. Any confession not made under free will is not admissible for evidence. 2. Whether the confession had its “factual truthfulness on trial” ? Consistency between confession and fact is an issue of trustworthiness and proof of evidence. In order for a confession to be admissible as the factual basis for a conviction, it must possess the quality of “voluntarinessand truthfulness of a confession”Obviously, a false confession cannot serve as a valuable proof of evidence. The issue of voluntariness, i.e. legality in obtaining a confession, has attracted the attention of both practicing lawyers and academia. Yet, for cases involving accomplices or co-defendants, a self-incriminated confession made by one party might implicate others party-litigants as well. Thus the trustworthiness of these confessions is very much doubtful. The usual courtroom practice and academic opinion is to require supplementary evidences reinforcing the truthfulness of a confession. However, are we comfortable that this will confirm the truthfulness of a confession? This is an issue of the truthfulness of confessions made by accomplices or co-defendants. The author is of the opinion that, besides supplementary evidence, there should be an opportunity of confrontation installed in the evidentiary investigation process to confirm the trustworthiness of a confession. This will not only strengthen the party-litigant's due process protection, but will also ensure that the criminal defendant does have a constitutional right to a fair trial. 。