A quality control system includes a control device, an output device, and an input device placed at at least an end point of a distribution channel of articles; the input device includes an input unit for receiving data on a changed environment portion and a communication unit that transmits the data, information about an input location, and an input time to the control device. The control device includes a storage unit for storing the mode of packing of the articles in the distribution channel, a reception unit for receiving the information from the input device, an arithmetic operation unit that calculates the number of articles deviating from the storage environment and estimates the stage of the distribution channel deviating from the storage environment, and a transmission unit for transmitting calculation result to the output device that is provided with a display unit.