Abstract:[Objectives] Chinese Alligator, Alligator sinensis, listed as the first level protected animals in China, is an ancient and rare reptile which is endemic to China. There is no report on the cooling treatment for hibernation in North China. In this study, the 5 Chinese Alligators reared in Beijing Zoo were artificially cooled for hibernation during November 2020 to May 2021, in order to understand the characteristics and environmental needs of hibernation and the relationship between the environmental temperature and the behavior, also to explore the behavior ethogram during hibernation and establish a suitable way of controlling temperature for hibernation, which will provide a reference for safe overwintering and feeding management in North China. [Methods] The simple planar graph of the environment shows in Fig. 1. During the study, the environmental selection and behaviors of the Chinese Alligators were observed in each hibernation periods, the body temperatures were monitored during deep hibernation period, and the changes of behavioral indicators and biological indexes before and after hibernation were analyzed. ANOVA was used to analyze the variance between different distribution areas. Paired-Samples T Test was conducted to analyze the difference before and after hibernation and the difference periods. [Results] The animals were in primary hibernation when the average room temperature were 13.00 ± 3.10 ℃ (range 9.4﹣20.0 ℃) (Table 1, Fig. 2). The animals were in deep hibernation when the average room temperature and water temperature were 11.35 ± 2.60 ℃ (range 7.0﹣ 13.0 ℃) and 9.60 ± 2.09 ℃ (range 6.0﹣11.0 ℃) respectively, when the average room temperature was 12.17 ± 1.95 ℃, the animals were in deep hibernation, and when 10.54 ± 3.01 ℃ the minor reaction to human and external interference. The animals were in recovery period when temperature were 15.50 ± 1.77 ℃ (range 12.0﹣18.4 ℃). The body temperature of the animals was 10.9 ± 0.55 ℃ during the deep hibernation, and the whole hibernation period was nearly 7 months. During hibernation period, the inactivity behaviors mainly includes hibernating, piling up and hiding, the activity behaviors mainly includes crawling, diving, swing tail, open eyes, shaking head, rising head in water, putting head on something, warning exhalation and roaring. The percents of the inactivity behaviors frequency were 46.5% in the primary period, 76.0% in deep period, and less than 10% in the recovery period (Table 2). Most of the behaviors have significant differences between each hibernation periods (P < 0.05). There were individual differences in habitat selection in each hibernation stage. In the primary hibernation period, most individuals were on the land (89.4%). In the deep hibernation period, most individuals mainly hibernated in water and occasionally on land (75.8% in water), while all individuals were prefer to the pool during recovery period (90.4% in water) (Fig. 3). The distribution sites of the Chinese Alligators in land-area were mainly in the depressions area around the plants, which were consistent in each hibernation period (Fig. 4). In the water, they were mainly in the area where was less interference and with the low stones on the edge of the pool, the distribute percent was more than 95% (Fig. 5). There was no significant difference in of the biological indexes before and after hibernation (P > 0.05, Table 3). After hibernation, they began to eat at 26.0﹣28.0 ℃. [Conclusion] The results showed that, the Chinese Alligators were in hibernation when the average room temperature and water temperature were kept at 7.0﹣13.0 ℃ and 6.0﹣11.0 ℃ respectively in North China. By artificial cooling and enriching the habitat types of hibernation environment, the animals could be safe overwintering in hibernation, and the environmental temperature, humidity and environmental stability were the important factors to hibernation.