Chinese Sturgeon (Acipenser sinensis), listed as the first level protected animals in China, is in extremely critically endangered status. The aquarium can be used as the major education and ex situ base for species conservation. In this study, the free-swimming velocity and respiratory frequency of 40 individuals distributed in 6 age groups (from 3 to above 30 years old) were observed respectively, and the behavioral changes of 9 sturgeons (♀ 6, ♂ 3) in quickly gonadual development stage (from the later-stage Ⅱ to stage Ⅲ) were compared (Table 1), in order to find the rules of these parameters to make the baseline for perfecting the cultured technology. Among the 40 individuals, eight Sturgeons of them were 3-year old with a total length of 122 ± 12 cm, body weight 8 ± 2 kg (n = 8); The sturgeons above 30 years, were 335 ± 8 cm in length and 220 ± 15 kg in weight (n = 4) respectively (Table 2). The swimming velocity of all sturgeons was 44.46 ± 5.62 cm/s (range: 30﹣60 cm/s), there were no significant differences between individuals in different age groups (P > 0.05, Table 2). The respiratory frequency during swimming was decreased significantly with the increase of age (P < 0.05), it was 10﹣20 times/min in the approaching mature age (17-year) and above, while it was 30﹣40 times/min in the younger groups (3﹣7 years) (Table 2). The swimming velocity and the respiratory frequency were significantly increased in quickly gonadual development stage when compared to the early stage of gonadual development, which were from 34.17 ± 10.06 cm/s to 47.32 ± 11.99 cm/s and from 17.3 ± 7.0 times/min to 30.7 ± 9.0 times/min, and the average enhanced percentages were 50% and 60% respectively. This indicated the swimming behavior of these animals changed significantly. As a result, the scope of the two behavior parameters can be set down with the age and development stage changing respectively, which can be used as the reference of the physical evaluation in the aquarium.