Abstract: Plant MADS-box genes are a family of highly conserved transcription factors involved in many different developmental processes,including flower development. To elucidate the molecular mechanisms of floral development in the dicotyledonous species lisianthus (Eustoma grandi florum), we isolated cDNA of four flower-specific MADS-box genes from this plant by the method of 3' rapid amplification of cDNA ends using degenerate primers designed according to the MADS-box protein family conserved region from flower buds. Sequence and phylogenetic analysis indicated a high degree of predicted protein sequence identity with DEF from Antirrhinum majus, FBP3 and FBP6 from Petunia, and SEP3 from Arabidopsis thaliana. The four genes were termed EgDEF1, EgGLO1, EgPLE1 and EgSEP3-1, respectively. Alignment of the predicted aminoacid sequences from these genes, as well as with that from previously published subfamily members,revealed the MADS, intervening (I) and keratin-like (K) domains. Gene-specific RT-PCR performed with RNA isolated from the vegetative organs and floral organs revealed both EgDEF1 and EgGLO1 strongly expressed in petals and stamens. EgDEF1 expression was strongly detected in sepals and ovules,but EgGLO1 express ion was weak in sepals and not detected in ovules. EgPLE1 is specifically expressed in stamens, carpels,and ovules , but the expression in stamens was low. EgSEP3-1 was strongly expres sed in four flower whorls. Thus, the four MADS-box genes are expressed specifically in the floral organs of lisianthus.