Sensor networks integrated with cloud computing platform provides a promising way to develop monitoring system for elderly people especially dementia patients who need particular care for their normal life. In our work, we aim to design a comprehensive, unobtrusive, real-time, low-cost but effective monitoring system to help caregivers for their daily healthcare work. The system design has been finished and the entire experimental environment including sensor network and cloud model has been set up in our lab to collect simulated data and one health care center to collect real data. Though the system has been partially implemented due to time limit, the experiment results are encouraging.