LBD gene with LOB (lateral organ boundaries) domain structure, which plays very important role in plant development. Base on bioinformatic method, the LBD genes of Nicotiana Tabacum were screened with the LBD gene sequences of Arabidopsis. The sequence structure, phylogenetic relationship and expression pattern of the identified gene sequences were analyzed. The result show: a total of 98 LBD genes were identified from tobacco with simple genetic structures contained 1-3 exons generally. Tobacco LBD gene family be divided into two types (I and II). All LBD members had conserved domain CX2CX6CX3C, however, the type II genes had secondary structure of coiled coil made of LX6LX3LX6L. Furthermore, LBD genes can be divided into 5 sub families (Ia, Ib, Ic, Id and II) by their phylogenetic relationship with Arabidopsis. 36 members have EST evidenc; the analysis of EST, array data and transcriptome show that the LBD genes had different expression patterns and tissue specificity. These results provide abundant information for the LBD genes family further functional analysis.