The Hooded Crane (Grus monacha) is a globally threatened waterbird. From October 2007 to April 2008, the time-activity budgets of the cranes were recorded in Shengjin Lake, the main wintering area for the crane in China. Instantaneous scan sampling was used to observe the behavior of the wintering cranes. Foraging and alerting were the most frequent diurnal behaviors, with average diurnal time-activity budgets of 60.4% and 15.5%, respectively. The time budgets for diurnal behaviors were significantly different from 07:00 to 18:00 for all behavior categories except for alerting and social behaviors. Over the winter period, the time budget for foraging increased from 56.2% in the early stages to 65.7% in the late stage. However, the percentage of time spent alerting decreased from 20.7% to 10.4% as winter progressed. In family groups, adults usually spent more time on maintenance, alerting, locomotion and social behaviors, and less time on foraging and resting than juveniles, in all wintering stages. In the early and middle of winter, the foraging time budget of adults was significantly different from that of juveniles, while at the late stage it was not. The alerting time budget of adults was significantly different from that of juveniles in the early and middle stages of winter, but the difference were less statistically significance in the late stage. The results imply that wintering cranes in Shengjin Lake exhibit different behavioral patterns over the different winter stages to adapt to the degraded and disturbed environment, and parental care of offspring should increase juvenile survival.