SQUAMOSA promoter binding protein-like (SPL) is one of the most important transcription factors in plant. The members of this family contain a highly conserved SBP (Squamosa-promoter Binding Protein) domain, and involve in regulating plant growth, secondary metabolism, hormonal signal transduction and abiotic stress. In this study, twenty-six SPL family genes (ItbSPL) were identified using the SBP Hidden Markov Model (HMM), Blastp, CDD and SMART from Ipomoea triloba (I.triloba) genome, which is a wild diploid progenitor of the sweetpotato. The ItbSPL members were unevenly distributed on 12 of the 15 chromosomes of I.triloba. Phylogenetic analysis with the newly identified 26 ItbSPL genes and 116 SPL genes from bryophytes, dicotyledons and monocotyledons showed that the 26 ItbSPL genes were classified into 7 sub-groups based on the similarity of conserved SBP domain with the orthologs in Arabidopsis thaliana. By analyzing gene structure and motif composition, the number of exons and motif of ItbSPL were different among different evolutionary clades. SPL genes from I.triloba and Arabidopsis were grouped together, suggesting a similar function of SPL genes. PsRNA Target prediction suggested 14 of the 26 ItbSPL genes contained complementary sequencesof miR156t, and 13 ItbSPL genes of them had PCR production. Furthermore, qRT-PCR showed the 13 ItbSPL genes had lowest expression in stem, where the expression of miR156 was highly accumulated, suggesting that the 13 ItbSPL genes might be the targets of miR156. Taken together, these results will be helpful for future studies on the identification, evolutionary and function analysis of SPL genes in hexaploid sweetpotato.