In order to explore the age and sex differences in physiological and biochemical indexes of blood in Red-crowned Cranes (Grus japonensis), 13 physiological indexes and 15 blood biochemical indexes were determined and compared using samples from 42 (adult 24, sub-adult 18) captive Red-crowned Cranes at the Shenyang Zoo. The results showed that all the indicators had no significant difference between the sexes (P > 0.05, Table 1 and 2), but there were significant differences in the serum creatinine (adult 37.05 ± 17.03 mmol/L, sub-adult 22.57 ± 11.68 mmol/L), serum uric acid (adult 878.22 ± 514.41 mmol/L, sub-adult 426.17 ± 207.74 mmol/L), and serum triglyceride (adult 7.73 ± 4.75 mmol/L, sub-adult 3.51 ± 4.07 mmol/L) indicators between adult and sub-adult (Table 3 and 4). This implies that the Red-crowned Crane might adopt the same or different ecological adaptation strategies in different adult and sub-adult periods.