The Child Seat Safety System provides drivers (common vehicles) with an alarm and monitoring system for the attachment of safety harnesses and temperature readings for respective child seat occupants within the car. The monitoring component details the attached “status” of said harnesses through indicator lights on the main operator dashboard along with on the system device. Alarm features automatically warn either the driver or surrounding bystanders or emergency personnel of alarm situation including temperature variances, harness disengagement, accident or unattended occupant warnings. The Child Seat Safety System can reduce the risk of small children being injured due to unattached seat belts during accident, braking or collision, and can reduce exposure to unhealthy temperatures either during driving or from extended lengths of time being unattended in a car.