To make life easier for students, our goal is to design a system to monitor library seating. Our product will be designed for and tested in the library at Zhejiang University International Campus. This system will contain a physical sensing unit and a web interface application, which uses a cloud database to support data communication between the two subsystems. There are three states for each seat: occupied by people, occupied by items, and unoccupied. The sensing unit will combine different types of sensors, such as the infrared sensor and the ultrasonic sensor, to determine the state of each seat. Then the occupancy data will be sent to the cloud for the web interface application to visualize seat availability.