The theory of article 169 of The Code of Criminal Procedure has been lost since it was adopted by the law in the late Qin and early Republic. This article traces back to the articles and historical material of the adopted period and compares them with comparative law and history of legal systems, noting that ordering the defendant to leave the court and examining separately is an exception permitted by law of the principle that prohibits the ex parte verdict. Article 169 of The Code of Criminal Procedure is the so-called specially provided in paragraph 1, article 281. Therefore, those who violate this article may also constitute unlawful trial without the presence of the defendant, which is on its face contrary to law, according to subparagraph 6, article 379. In the amendment in 2003, the reason of the amendment deviated from the right to be heard and the right to be present, however it was led to the Confrontation and further affected following development of the judicial opinions. This is still open to discussion.