According to the ARP (Auxin-repressed protein) gene fragment sequence,which was obtained from the SSH (suppression subtractive hybridization) library constructed by iron-deficiency and normal leaves.The full length of ARP was cloned by the method of RACE (repeat amplification of cDNA end).The ARP expression levels were analyzed by qRT-PCR (real-time quantitative PCR) technology.The results showed that the IAA content in leaf was decreased gradually with the increasing of iron-deficiency degree;the full-length cDNA of ARP was 707 bp,its coding region covered 351 bp and encoded a polypeptide containing 116 amino acids.It was predicted that the ARP might positioned on the microbody in cell,was a nontransmembrane protein with non secretory type,had a conserved domains with auxin gene family;and its molecular weight was 12.82 kD;There were positive significant differences between ARP relative expressions in leaves with different iron-deficiency degrees.The ARP expression increased with the increasing of iron-deficiency degree.It was speculated that the endogenous IAA level was negatively regulated by the ARP in iron-deficiency leaves,to control the leaf growth and development.