Haynaldia villosa (2n=14, VV), a wild grass of the subtribe Triticeae, serves as potential gene resources for wheat genetic improvement. In this study, the proteome characterization during grain development of Yangmai 5 and Yangmai 5-H. villosa 6VS/6AL translocation line was investigated by a comparative proteomic approach. Two-dimensional electrophoresis identified 81 differentially accumulated proteins (DAPs) during five grain developmental stages in wheat-H. villosa translocation line. These proteins were mainly involved in stress defense, storage protein, energy metabolism, protein metabolism and folding, carbon metabolism, nitrogen metabolism, and starch metabolism. In particular, 6VS/6AL translocation led to significant upregulation of 36 DAPs and specific expression of 11 DAPs such as chitinase, thaumatin-like proteins, glutathione transferase, α-amylase inhibitor, heat shock proteins, and betaine aldehyde dehydrogenase. These proteins mainly involved in biotic and abiotic stress responses. Further analysis found that the upstream 1500 promoter regions of these stress-responsive DAP genes contained multiple high-frequency cis-acting elements related to stress defense such as abscisic acid response element ABRE, methyl jasmonate (MeJA)-response element TGACG-motif and CGTCA-motif involved in oxidative stress and antioxidant response element (ARE). RNA-seq and RT-qPCR analyses revealed the high expression of these stress-defensive DAP genes in the developing grains, particularly at the early-middle grain filling stages.Our results demonstrated that 6VS chromosome of H. villosa contains abundant stress-defensive proteins that have potential values for wheat genetic improvement.