Nowadays, the quality of life in aspect of safety has been decreased, so the need of security system is increased. However, the commercial system price is inappropriate for the residence and small office uses. Therefore, this project is aimed to develop the security system for these uses. Based on opensource software, low-price web cameras and sensors, Bluetooth communication for interfacing with the cellular network, and the Internet, we developed a system with maximal performance but minimal developing cost. The final system is able to detect movement and motion, supporting up to 8 web cameras and 8 on-off sensors. Configuring, scheduling, and live video feeding are available via Internet access. Under abnormal circumstance, the system is able to record the images and videos, and alert the users via 3 different method: E-mail, SMS, and phone call.