Abstract: Sillago sihama is a tropical fish from India to the western Pacific. It is widely distributed in the coastal waters of southern China and is one of the most important economic fish species. The factor inhibiting hypoxia inducible factor-1 (fih-1) is a key factor in the hypoxia signal pathway. It plays an important role in the hypoxia adaptation in fishes. The fih-1 gene of S. sihama was cloned, and its cDNA sequence was 1280 bp, including an open reading frame of 1065 bp, encoding 353 amino. The structure prediction found that there was a JmjC conserved domain. Multi-sequence alignment and cluster analysis based on fih-1 amino acid sequences showed that the S. sihama was closely related to Larimichthys crocea and Lates calcarifer, bur farther to mammals, amphibians, and birds. The fih-1 was strongly expressed in the testis, ovary, and muscle, followed by the gill, heart and liver, but weakly expressed in the brain. The expression of fih-1 gene in gill and heart increased significantly after 1-hour hypoxia stress, and it continued to increase significantly after 6 hours. After 4 hours of normal dissolved oxygen, the expression decreased significantly but it was still higher than the normal level (P<0.05). This study revealed that fih-1 gene plays an important role in the hypoxic signal conduction pathway and provides candidate genes for carrying out and explaining the genetic mechanism of S. sihama.