In the macrocosmic perspective,the development trend of the rights and obligations of doctors and patients is regarded as changes in the healthcare mode.In the microcosmic perspective,it is regarded as a clarification and emphasis of the informed consent of the patients as required by laws and regulations.However,medical workers tend to neglect their obligation of informing the patients of the medical expenses to be paid out of their own pocket.In this consideration,informing the patients in writing of their self-payment in medical expenses is obligatory and important,i.e,the self-payment agreement is highly important in clinical work.This paper analyzed the legal at-tributes of self-payment agreement in the aspects of both the informed consent and the signing of the medical service contract,with discussions of the tining of signature,in the hope of inspiring and helping medical workers in their clinical practice.