This document describes the design and development of a cold chain monitoring system for vaccines. The system was created to ensure vaccine safety by strictly monitoring temperature from production to usage and allowing information sharing between all entities involved. It includes modules for vaccine suppliers, manufacturers, logistics providers, medical facilities, and functions for temperature monitoring, emergency reporting, and inspections. The system establishes authority levels and data access controls. It was tested using scenarios involving temperature deviations and ineffective vaccines to demonstrate how the system could quickly identify issues and improve safety oversight of vaccines. The goal is to implement such a system in Taiwan to better manage vaccine quality and trace any problems.