Abstract: The purchase of Private Supplementary Medical Insurance (PSMI) on the part of urban and rural residents are affected by three factors with other things being equal: whether the contract of PSMI permits the insured to select physicians to provide medical care in priority, whether PSMI withdraws the surplus outpatient fees after paying by the basic medical insurance and whether the insurer of PSMI provides information such as disease prevention, health consultation, health assessment and health education. In order to extend the coverage of PSMI, it is necessary to establish a close cooperation between the insurer of PSMI and medical organizations to provide privileged and prioritized medical care, to let the insurer of PSMI place the attention of withdraw of medical fees to the surplus outpatient fees after paying by the basic medical insurance, to let the insurer of PSMI provide the health promotion services such as disease prevention to the insured.