When new immigrants face medical malpractices, interpreter's importance and urgency is not hard to imagine. This article analyzes interpreter's different role play when facing with patients, relatives, medical personnel, and medical care institutions. This article also explains interpreter's function mentioned in the "Medical Malpractice Resolution and Compensation Act (draft)". In terms of interpreter's explaining function, it means passing objective facts. In terms of interpreter's communicating function, it means facilitating consensus building between patients and physicians. In terms of interpreter's caring function, it means exchanging feelings and experiences. This article states that the Taiwanese society should build consensus about legalizing interpreter's position when facing with medical malpractices. Interpreters should take educational training related to medical profession and interdisciplinary knowledge. Thus, patients' right to autonomy can be fulfilled and harmonious physician-patient relationship goal can be achieved.