Abstract: A pair of 23 bp primers, designed according to a conserved sequence of the APETALA1(AP1) gene which has an important function in floral development, were used to amplify a 648 bp fragment by polymerase chain reaction(PCR). The fragment was cloned into pUCm T vector, and then sequenced. A fragment in the middle of AP1 homologous gene named ZM AP1 gene was obtained. The result of sequence analysis indicated that there were two introns of 152 bp and 386 bp in the fragment, and the exons encoded 36 amino acids. The ZM AP1 gene has been registered in GenBank with the accession number AF356541. After the deduced amino acid sequence of the fragment was submitted to GenBank and blast with AP1 homologous gene of other plants, it was found that the homology reached 66%-88%. This result suggested that ZM AP1 gene might have the same function as other AP1 homologous gene.