Thestrictosidine synthase-like(SSL) gene family is a small plant immune-regulated gene family that plays a critical role in plant resistance to biotic/abiotic stresses. To date, very little has been reported on theSSLgene in plants. In this study, a total of thirteenSSLs genes were identified from poplar, and these were classified into four subgroups based on multiple sequence alignment and phylogenetic tree analysis, and members of the same subgroup were found to have similar gene structures and motifs. The results of the collinearity analysis showed that poplarSSLs had more collinear genes in the woody plantsSalix purpureaandEucalyptus grandis. The promoter analysis revealed that the promoter region ofPtrSSLs contains a large number of biotic/abiotic stress response elements. Subsequently, we examined the expression patterns ofPtrSSLs following drought, salt, and leaf blight stress, using RT-qPCR to validate the response ofPtrSSLs to biotic/abiotic stresses. In addition, the prediction of transcription factor (TF) regulatory networks identified several TFs, such asATMYB46,ATMYB15,AGL20,STOP1,ATWRKY65, and so on, that may be induced in the expression ofPtrSSLs in response to adversity stress. In conclusion, this study provides a solid basis for a functional analysis of theSSLgene family in response to biotic/abiotic stresses in poplar.