共同被告的陳述在刑事訴訟上的評價，一直都是困擾實務及學界的問題。什麼樣的情形下，程序上可能出現共同被告為本文第一個處理的部分。依照刑事訴訟法的規定，共同正犯並不一定是共犯，此將使得問題更為複雜。 再者，如何在程序上使用共同被告的陳述，且能確保其真實性，似乎可以補強證據加以佐證，惟在論理上是否一貫，可能有進一步討論之必要。 歸納近年來實務關於共同被告陳述的判決得以知悉，似乎認為被告的自白及共同被告的陳述有性質上有其相同之處，需有補強證據加以補強。為了解決相關問題，在制度上可能採取的方式有分離訴訟程序及承認被告證人適格的兩種作法。本文認為，唯有後者之作法才能根本解決此一困惑之問題。

The statement of the codefendant is the complex problem to the scholars. In the first part, we discuss the condition of the codefendant. According to Criminal Procedure, the codefendant is not equal to the accomplice; it makes the problem more complex. How to evaluate the statement of the codefendant and ensure its reliability is the following question. The other existing evidences may be able to qualify to that. But it may cause the conflict on the theory. From the recent judgments, we can conclude that supreme court treat the statement of the codefendant as the confession of the defendant and ask the other evidence when using them to prove the fact. To solving the relating problems, there are two possible ways: separating the procedure, and endow the defendant with the standing of witness. The article adapts the latter, because it can solve the problems fundamentally.