A preparation system for surveying operation of the present invention includes a mobile station disposed at a known observation point and a fixed station disposed at an unknown reference point. The preparation system includes an arithmetic step to determine the position coordinate of the unknown reference point based on positioning data received by the mobile station, positioning data received by the fixed station, and a position coordinate of the known observation point, and an assigning step to assign the unknown reference point whose position coordinate is determined as the known reference point.