Monitoring people’s stress has become an essential part of behavioral studies for physical and mental illnesses conducted within the biopsychosocial framework. There have been several stress assessment studies in laboratory-based controlled settings. However, the results of these studies do not always translate effectively into an everyday context. The current state of wearable sensor technology allows us to develop systems measuring the physiological signals reflecting stress 24/7 while capturing the context. In this project, we develop a stress monitoring system that provides objective daily stress measurements in everyday settings based on wearable sensors. This research is conducted in collaboration with the UCI THRIVE LAB at the Department of Psychological Science.