A system and method for classifying a vehicle occupant is disclosed. A base is installed in each of leg frames of a seat of a vehicle. A cover is installed above the base to be spaced apart from the base. Two weight sensors are installed between the base and the cover to support the cover, and configured to measure a load transmitted to the cover by the weight of a vehicle occupant sitting in the seat. A control unit receives load values measured by the weight sensors, and determines whether the vehicle occupant sitting in the seat is an adult or a child based on the received load values. A shock absorption member is interposed between the weight sensors and the base. A stopper is interposed between the base and the cover in order to limit a downward movement range of the cover in a case of overload.