ATPase is closely related to chilling tolerance. The EST sequence of chilling-repressed gene atpA encoding CF₁ α -subunit was obtained from Elumus sibiricus L. cv.'chuancao No.2' by reverse transcription-polymerase chain reactiom (RT-PCR) differential display. Full-length cDNA of 1 754 bp was cloned by 5 ′ RACE. The atpA has an open reading frame (ORF) of 1 518 bp that encodes a precursor protein of 505 amino acid residues. The deduced amino acid sequence exhibits 95%, 94% and 94% positional identity with atpA of wheat, rice and corn, respectively. Northern hybridization analysis on mRNA from treatment at 2 ℃ and post-treatment, in total of 13 time stages, showed that its RNA transcript was strongly inhibited after 12 h of chilling stress, whereas it was clearly higher than control during 4~8 h of chilling stress and 16~24 h after removing stress. This result provides new clue for revealing the CF₁α -subunit role to ATPase in plant defence against chilling stress