Bone marrow mesenchymal stem cells (BM-MSCs) have been suggested to participate in the physiologic healing process of tissue injury by being recruited from the bone marrow and home into the injured site through circulation. To investigate the effect of diabetic hyperglycemia on circulating BM MSCs, which would affect their differentiation, two-dimensional electrophoresis (2-DE) was performed to determine the pattern of protein expression in BM MSCs. After exposure to high (25 mM) glucose concentration for 3 days, six proteins were found to be down regulated by less than 50% (ERp29, Triosephosphate, ATP synthase, phosphoprotein enriched in asprocytes 15, putative glycogen phosphorylase and myosin light chain 3) relative to the control. In addition, 2 proteins (LPLUNC1, isoAsp carboxyl methyltransferase) were neo expressed and one (beta-galactoside binding lectin) protein was shown to be up regulated by more than 300% as a result of hyperglycemia. These results may provide a framework for understanding the molecular mechanism and relationship between hyperglycemia and stem cells.