This paper is to integrate information technology and medical-related technologies to develop a Healthcare Information System for geriatric care. This system not only can process geriatric consultation services, and ensure that all patient's information are stored in standardized format, but also provide medical personnel for statistical analysis and processing purposes. Furthermore, this paper uses the Apriori algorithm of data mining for helping doctors to find out the relationship of geriatric syndrome. Moreover, by using the result of association rules, we found out five common aging diseases. Through this information system, we will be able to ameliorate the quality of medication and the efficiency of work in hospital.