To investigate the relationship between the content of gibberellins(GA) and the expression of its signal transduction related genes in leaf of pear plant with different degree of iron-deficiency,we used the in vitro plantlets of ‘Dangshansuli’ pear(Pyrus bretschneideri Rehd.) cultured in agar medium treated with different concentration of Fe-EDTA as experiment material in this study.GA contents in leaf were tested by the Enzyme-Linked ImmunoSorbent Assay(ELISA).According to the sequence of homologous gene from NCBI library,the full length of GA2ox gene was cloned by the method of the Rapid-amplification of cDNA Ends(RACE).Four alleles of GID1 and DELLA blast from pear genome database.The levels of relative expression of GA2ox gene,four alleles of GID1 and DELLA were analyzed using real-time quantitative reverse transcription-PCR(qRT-PCR).The results showed that:(1)The GA content in leaves increased as the iron content decreased in medium.(2)The full length of cDNA fragment of GA2ox gene cloned was 1 014 bp and had been submitted to the Genbank with the accession number of KJ008976.(3)The levels of relative expression of GA2ox gene at different degree of iron-deficiency did not increased as GA contents raised.The levels of relative expression of the four alleles of GID1 all increased as degree of iron-deficiency become severe.There were positive correlation between GA content and levels of relative expression of the four alleles of GID1.Only the levels of relative expression of DELLA1 increased as the degree of iron-deficiency become severe,that was most sensitive to the stress of iron-deficiency.It was speculated that the iron-deficiency could accelerate the synthesis of GA and would not promote active GA into inactive ones.