Abstract:The B3 superfamily plays vital roles in plant growth and development, especially in related signal transduction pathway as a kind of transcription factors. All members of the B3 superfamily share the B3 DNA-binding domain of approximately 110 amino acids. 97 members of the tomato B3 superfamily were all confirmed according to BLAST from the protein databases of tomato using the conserved B3 domain. Phylogenetic trees, chromosomal localization, function domain of all B3 members, tissue and induced expression patterns of partial B3 members were all analyzed. All the members were divided into four subfamilies, including LAV, ARF, RAV and REM, with 4, 22, 9 and 62 members, respectively. The branch of each subfamily was obviously distinguished from others in the phylogenetic tree, with analyzing the function domains of all members. All members of the B3 superfamily were assigned to each chromosome, and each subfamily distributed in different patterns and frequency. Partial members of B3 superfamily have different tissue and induced expression patterns, and responded to different signals.