Abstract: A real-time alarm system comprises an image capturing element, a network transmission system, a control processing unit and a mobile device. The image capturing element is installed on different sites to generate image information. The image information is transmitted through the network transmission system with one end linking to the image capturing element. The control processing unit is linked to the network transmission system and includes a server, and contains preset information to compare with the image information to generate comparison information. The comparison information is analyzed by a preset algorithm to judge behaviors of objects in the images. The mobile device is linked to the control processing unit to receive the image information. After the control processing unit judges specific behaviors, it actively informs the mobile device to record a video for a selected duration to be seen anytime at a remote site.