A witness is the third person to describe his/her own past experience to a judge or a prosecutor. Because a witness’s past experience is mostly personal and cannot be substituted, the presence and truthful testimony of the witness is largely influential for the preciseness of the trial and prosecution. Therefore, every citizen has the obligations to be a witness, which include:　

1.The obligation to appear before court or a prosecutor. 

Upon receiving the subpoena signed by a judge or a prosecutor, the witness has the obligation to appear before court or a prosecutor in order to testify unless with good cause { such as incapability to appear due to serious illness, natural disaster, traffic deadlock }. Based on the principal of direct-trial and verbal-trial, the testimony principally cannot be substituted by oral statement from others or written report by the witness himself/herself. If the witness violates this obligation, under the criminal procedure code, he/she shall be fined up to 30000 NT (consecutively if so violates), and an arrest warrant will be issued against him/ her.　

2.The obligation to testify.

A witness has an obligation to make a statement truthfully without disparities with his/ her own past experience. Any violation of this obligation may give rise to the penalty of a fine up to 30000NT. Nevertheless, with the inconvenience to testify due to close-relatives relationship between the witness and case parties or a specific title of the witness, such as spouse, family member, witnesses with occupational ground (medical doctor or lawyer) questioned about confidential matters, the witness is entitled to the refusal of giving testimony. However, it should be the judge or the prosecutor, not the witness himself/herself, deciding upon the eligibility of the witness’s refusal to testify.