The aim of this study was to perform molecular and bioinformatics analysis of IGFBP2 gene promoter in association with some economic traits in indigenous Makuee (MS) and Lori-Bakhtiari (LB) breeds. DNA was extracted from blood samples of 120 MS and 200 LB and a 297 bp fragment from the upstream sequences of studied gene was amplified and genotyped by single-strand conformational polymorphism (SSCP) technique. Two genotypes of AB and BB were seen in MS and LB breeds. Then one sample from each genotype was send to sequencing. After obtaining the sequencing result, the sequences homology was performed on the National Center for Biological Information NCBI server by basic local alignment search tool (BLAST) program. The alignment of the obtained sequences and their comparison with reference sequences from the Gene Bank were done using CLUSTALW multiple alignment tool of BioEdit software. In addition, the DNASIS MAX software was used to identify DNA motifs. The bioinformatics analysis revealed differences in sequences of IGFBP2 between observed genotypes. Ten motifs in promoter sequence of IGFBP2 genes were seen, so that the CAP_site motif was most abundant in both fragments motif. Statistical analysis using general linear method model (GLM) procedure of SAS software showed significant (P<0.05) association of IGFBP2 with thigh round (TR) trait in Makuee sheep. Further studies in other indigenous sheep breeds and investigation of other genetic regions along with regulatory sites seem to be necessary. تفاصيل المقالة