Picea mongolica is a rare and precious tree species in China, with excellent resistance to drought, cold and sand burial. LBD (lateral organ boundaries domain) is an important transcription factor in plant lateral organs, which plays a key role in plant growth and development and stress response. LBD genes have, however, not yet been reported in P. mongolica. In this study, the LBD gene was identified by the genome data of Picea abies and transcriptome data of P. mongolica and bioinformatics analysis were performed. The expression levels of the LBD gene in different tissues (shoot tip, main root, lateral root, stem and leaf) and under salt stress were detected by qRT-PCR. The results show that a total of 30 LBD genes (PmLBD1-30) were identified in the transcriptome of P. mongolica. Their protein sequence length ranges from 119 to 309 aa, molecular weight ranges from 10.5 to 33.4 KDa, and isoelectric point (pI) ranges from 5.15 to 9.26. Cell-PLoc subcellular localization predictions suggested that all LBD proteins were located in the nucleus. Besides, all LBD protein domains and gene structures are highly conserved and composed of similar motifs. These PmLBDs were divided into 5 categories (Class Ia~e) according to the phylogenetic tree, containing 4, 11, 5, 1 and 9 genes respectively. qRT-PCR showed that PmLBDs were expressed in different tissues. For example, PmLBD2/5/18/19 were highly expressed in stems, and PmLBD9/20/23 of Class Ib were strongly expressed in lateral roots; The expression of most LBDs strongly responded to salt stress, 17 PmLBDs were up-regulated and 6 PmLBDs were down-regulated under salt treatment, and the expression of genes in the same subfamily showed a similar trend. These results laid the foundation for further investigation of abiotic stress function and molecular breeding of the LBD gene family in P. mongolica.