This paper is to integrate information technology and medical-related technologies to develop a healthcare information system for Comprehensive geriatric assessment (CGA). 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. Moreover, this paper uses the Apriori algorithm of data mining for helping doctors to find out the relationship of geriatric syndrome. The systems of this study can enable organizations to meet their business objectives for increasing service capacity, cost control, revenue generation, while maintaining high quality of care for the patients in geriatric care. Furthermore, making the theories and applications of medical informatics will be more extensive and convenient for researches and healthcare-related industry.