PROBLEM TO BE SOLVED : To provide a system for medical information sharing capable of enhancing efficiency and convenience in fields of medical treatment and improvement in health with providing environments enabling to promote provisions of medical information from users.SOLUTION : In the system, a server system 11 connectable from medical institutions is equipped, the system 11 comprises a customer' s data storage part 18 to manage verification information on a customer necessary to verify the customer, a medical data storage part 20 to receive medical information on the customer together the verification information from the institutions and store the medical information if the correctness of the medical information is recognized based on the verification information and a medical information providing part (data transmission part) 17 to receive requests from the customer for the medical information together the verification information from any medical institutions and provide the medical information on the customer to the institutions if validity of the requests is recognized based on the verification information.