Abstract: A monitor system includes an outdoor doorbell module integrated with video and audio transmission, an indoor remote receiver and a signal transmission interface. The doorbell module includes a depressible button and a micro-camera and a sound detector actuated by the button to obtain visual image and sounds of the visitor. The remote receiver includes a signal receiver circuit to receive the doorbell actuation signal and the visual image and sounds from the doorbell module, an alarm generator activated by the doorbell actuation signal to ring, and a driver circuit generating control signals to control a monitoring device and a recording device. When the button is actuated by the visitor, the remote receiver receives the doorbell actuation signal and generates the ring. At the same time, the doorbell module activates the micro-camera and the sound detector to obtain visual image and sounds of the visitor.