Abstract: The molecular cloning and sequence characteristic analysis of Forkhead Box protein-1 (FoxO1) CDS region were investigated using the gonad tissues of Alligator sinensis in the resent research. Immunohistochemistry was used to detect its expression patterns in in peripheral tissues such as stomach, intestine, and lung. Immunofluorescence (IF), RT-PCR and Western blot were used to investigate the temporal and spatial expression patterns in the gonadal tissues of Chinese Alligator at different days of age (17, 63 and 96 days of age), and to investigate the biological functions in the gonadal development of Chinese alligator. The complete coding region of FoxO1 gene and predicted coding amino acid were 1941 bp and 646 aa, respectively. Homology comparison and phylogenetic tree analysis showed that FoxO1 of Chinese alligator was more closely to birds than reptiles such as Pelodiscus sinesis and Protobothrips mucrisquamatus. Other vertebrates such as mammals, teleost, and amphibians were also grouped into subgroups, suggesting that FoxO1 is both functionally conserved and species-specific. FoxO1 protein expressed in the newly hatched crocodile gonadal complex, lung, stomach and intestine. FoxO1 expressed significantly higher in the ovarian tissue at the 17^th days post-hatched than that at the 63^rd and 96^th days post-hatched individuals. FoxO1 mainly expressed in the adrenal and mesonephrons but weakly expressed in the cortex of ovarian collected at the 17^th days post-hatched, and its irregular and randomly distribution was gradually upregulated in the cortex at the 63^rd days post-hatched individual. FoxO1strongly expressed in the cortex of the 96^th days post-hatched individual ovarian tissues where oocytes were more developed. FoxO1 mRNA level was no significant difference in the gonadal tissues of Chinese alligator at different periods. These results provide important reference for enriching the regulation mechanism of oogenesis of Chinese Alligator.