Abstract: A plasma membrane intrinsic proteins（PIPs）gene，designated GhPIP1;1，was cloned from petals on gladiolus（Gladiolus hybridus‘Eerde’）flowers by RT-PCR and RACE. The full cDNA sequence of GhPIP1;1 is 1 130 bp，containing an open reading frame（867 bp）and encoding a protein of 288 amino acids. The GhPIP1;1 genomic DNA（2 098 bp）was also cloned，which contains 4 exons and 3 introns in its coding sequence. Two highly conserved NPA（Asn-Pro-Ala）motifs of aquaporins were found in GhPIP1;1. Homology of amino acids sequences between GhPIP1;1 and PIP1 from Iris hollandica was up to 94%. The semi-quantitative RT-PCR analysis showed that GhPIP1;1 gene was expressed in petals，stamina，pistils，stems，bracts，and leaves on gladiolus flowering stems，and the expression level was the highest in petals，and the lowest in leaves. Then after further expression analysis of GhPIP1;1 gene in petals of gladiolus florets during opening process，it was found that it maintained high and relatively stable levels from bud stage to flower full opening，however it was obviously down-regulated during the subsequent flower wilting.

Key words: gladiolus, Gladiolus hybridus, aquaporin, molecular characterization, gene expression