Code of Civil Procedure Article 308

A witness may not refuse to testify on any of the following matters despite the existence of the situation provided in the first or the second subparagraph of the first paragraph of the preceding article:1. The birth, death, marriage, or other matters relating to the identification of a person who cohabits or used to cohabit with the witness;2. Property matters arising from a family relationship;3. The existence and content of a juridical act known to him/her in the capacity of a witness; or4. An act relating to the legal relation in dispute, which he/she conducted in the capacity of the predecessor in right or as an agent of a party. Despite the existence of the circumstance provided in the fourth subparagraph of the first paragraph of the preceding article, a witness may not refuse to testify if he/she is relieved from the confidentiality obligation.
中文原文 民事訴訟法第308條
證人有前條第一項第一款或第二款情形者,關於下列各款事項,仍不得拒絕證言:
一、同居或曾同居人之出生、死亡、婚姻或其他身分上之事項。
二、因親屬關係所生財產上之事項。
三、為證人而知悉之法律行為之成立及其內容。
四、為當事人之前權利人或代理人,而就相爭之法律關係所為之行為。
證人雖有前條第一項第四款情形,如其秘密之責任已經免除者,不得拒絕證言。

English translation for reference only; the Chinese text prevails. Not legal advice.