Abstract: Determining the subject of exercise of the patient informed consent is the basis for building a medical informed consent system. After an empirical analysis， it was found that the courts did not distinguish the concept of relatives， family members， and close relatives when determining the scope of the subject. It was also found that the courts replaced the review of the mental capacity with the capacity system， and did not distinguish between inappropriateness and incapability when examining the subject's ability to agree. It was also found that the court basically denied that the patients have rights to consent under the intended agent， and did not recognize that the close relatives have the right to exercise decision-making authority when judging the subject order. Aiming at the misunderstanding in judicial practice， we should use the concept of close relatives and expand it to include widowed daughter-in-law， and son-in-law， establish mental capacity as a criterion for judging whether there is medical consent， add provisions that refine investigation factors that cannot be notified and basic situations that should not be notified， make clear that the principle of others making medical decisions is in the best interest of the patient， define the order of close relatives from the perspective of kinship， property dependence and decision-making ability， and abolish the approval procedure for the person in charge.

Key words: patient informed consent, scope of the subject of exercise, ability to agree of the subject of exercise, order of the subject of exercise, medical privilege of the subject of exercise, emergency treatment