Chinese Alligator (Alligator sinensis) is a rare species endemic to China. Up to now, the growth and reproduction of Chinese Alligator have been received much attention. In this paper, we used the color doppler ultrasonic diagnostic apparatus (VIVIDⅠ) to examine the abdomen of 17 adult female alligators in March (hibernating period) and June (breeding season) 2014, respectively, and the sizes of ovarian follicles in March was analyzed by regression analysis using SPSS 19.0 software. The internal organs including heart, liver and intestine were clearly observed. A total of 41 follicles during hibernating period and 42 follicles during breeding season were examined. Follicles in low or no echo dark area were immature during hibernation. Follicular development in reproduction period was basically the same as in March. A handful of follicles in high echo dark space had formed yolk granules while others in high echo light area had formed the vitelline membrane. Regression analysis of 19 follicles′sizes indicated that the ovary size increased with the follicular development. The shapes of organs as well as the structure of heart were readily discernible with ultrasonography. Process of blood flow in heart could be detected by color doppler ultrasound. Heart rates were 12 and 43 counts per minute in hibernating period and breeding season, respectively. We show that ultrasonography is a low-invasive way that can be used to assess follicular development. In Chinese Alligator, which increases accuracy of sieving in breeding alligator.