Abstract:YABBY family is a small plant-specific gene family, with a typically N-terminal C2C2-type zinc finger domain and the C-terminal helix-loop-helix YABBY domain. By homologous sequence analysis, a YABBY transcription factor was cloned from tomato (Solanum lycopersicon), and named SlYABBY5(GenBank accession number: AK246138). By bioinformatics analysis, the length of SlYABBY5 ORF is 549 bp, encoding 182 amino acid residues with relative molecular weight of 20.58 kD and an isoelectric point of 8.78. By real-time PCR analysis, SlYABBY5 gene might be involved in the development of tomato fruits and leaves. Expression of SlYABBY5 down-regulated under the treatments of IAA, ABA, GA3, ASA and low temperature stress, while up-regulated under salt stress and leaves wounding. Our results suggest that SlYABBY5 might participate in the growth and development of tomato and abiotic stress responses, and provide the basis for unrevealing the function of SlYABBY5 gene in tomato growth and development as well as stress signaling pathway.