From October 2006 to April 2007, wintering behaviors and the daily cycle of Black-necked Cranes (Grus nigricollis) were observed with instantaneous and scan sampling methods at Dashanbao National Nature Reserve, Zhaotong, Yunnan. During the wintering period, to meet wintering energy needs Black-necked Cranes spent most of their time feeding, which was about 53.05±4.93%. Other behaviors such as vigilance, searching, maintenance, walking, flight, and fight were 18.75±2.65%, 10.38±1.34%, 10.32±4.93%, 4.90±1.59%, 1.70±0.38%, 0.55±0.41%, 0.36±0.25%, respectively. Our results indicated that roost departure time had positive correlation with sunrise time, while roost arrival time had negative correlation with sunset time. One-Way ANOVA analysis showed that the eight wintering behaviors of Black-necked Cranes had significant differences between every one-hour period (09:00－18:00) and over the five month period (2006-11－2007-03). There were two feeding peaks in the morning and afternoon, with one maintenance peak at noon. Partial analyses showed that environmental temperature affected wintering behaviors independently, while environmental moisture had the opposite effect on behaviors dependent on environmental moisture. When the temperature was high, feeding was low and maintenance was high. When the temperature was low, maintenance was high and feeding was low.