In this paper, we developed a system that could assist appropriate activities for medication adherence of the elderly. It employs a proactive knowledge which is represented as templates predefined for their medication activities. The knowledge-based assistance depends on the contexts considerably, which the system can recognize by continuously monitoring the current position and the time-schedule for their medications. The monitoring is performed with ultrasonic sensors and infrared sensors mounted in a display and a pillbox mainly. According to the recognized contexts, the medication activities can he serviced through old person-friendly multimedia display. In special, since the knowledge is well-defined by XML, only its content modification can provide a variety of services individually customized to the elderly.