"Informed consent"is an important ethical principle that was first used in medical research and clinical care,and it mainly refers to the process of informing the participants(subjects and patients)of the possible effects of an experiment or treatment before it is carried out,and making a decision about whether to agree to participate in the experiment or treatment.This paper first describes the events related to informed consent that occured in medical research and clinical practice,and then discusses the issue of informed consent in linguistics and applied linguistics research,and it finally analyzes the relationship between the issue of informed consent and the research project by examining a hypothetical research project.The purpose of this paper is to remind linguistics and applied linguistics researchers of the importance of obtaining informed consent from subjects when engaging in research involving human participants.