The invention discloses a system and a method for accurately measuring a structure. A reference instrument mounted in a fixed location provides GPS reference information. A plurality of responders respectively installed at a plurality of positions of the structure acquire acceleration information through an acceleration sensor and respectively measure a plurality of real-time kinematic (RTK) displacement data based on the GPS reference information. The responder synchronizes acceleration information with the measured plurality of RTK displacement data to generate a packet to be transmitted. An operation processor receives the acceleration information and the plurality of RTK displacement data and calculates structural response information. With the GPS and accelerometer, it is possible to accurately measure the dynamic behavior of structures including high-rise buildings, bridges, dams, and ports.