Energy expenditure strategy of birds that suffered human disturbance is interesting because it affects birds' fitness, which is influenced by daily activities budget and habitats characteristics of birds involve in. It is important to migratory waterbirds inhabited in paddy field accommodate energy configuration response to risks from human disturbance as this kind of habitat is increasing important for waterbirds over the world. To better understand the energy expenditure in disturbance environmental conditions, here, using Tundra Swan Cygnus columbianus wintering in a paddy field of Shengjin Lake, China, we employed a focal sampling approach to record their responses and calculatee the diurnal energy expenditure (DEE). The percent of time being vigilant and it's energetic cost, a vigilance bout and frequency, swimming frequency under disturbed situation were significant longer than those under the undisturbed situation. The energetic costs of alert increased with the interference time and decreased with interference distance adversely. Due to disturbance reduced high-cost feeding and increased low-cost alerting, the DEE of swans under disturbed situation was less than that under undisturbed situation.