Abstract: The expression of hypoxia-inducible factor 1α gene(HIF-1α) in the lung of ascitic broilers was studied in comparison with healthy broilers.cDNA encoding HIF-1α from the lung of ascitic broilers was transfected into E.coli DH5α by using pMD18-T vector.Sequence analysis showed that the cloned 1 576bp cDNA and the deduced amino acid sequence shared 99% and 98% homology respectively with chicken embryo HIF-1α cDNA. The expression of HIF-1α in the lung of 4 healthy broilers and 4 ascitic broilers were then examined by RT-PCR. Results showed HIF-1α mRNA abundance was significantly higher in the lung of ascitic broilers than that in healthy broilers（P<0.01）. The result suggested that HIF-1α may be involved in the development of ascitic symptom induced by pulmonary hypertension of broilers.