Abstract: Objective To find a suitable substitute for fetal bovine serum so as to efficient expand mesenchymal stem cells. Methods The biological characteristics of bone marrow-derived mesenchymal stem cells cultured in adult type AB serum，AB-type cord serum and fetal calf serum were compared, including the cell morphology, immunophenotype, cell cycle, growth curve. Results There is no obvious difference between the three. Conclusion These date suggest that type AB serum of healthy adults can be as an alternative of fetal bovine serum for mesenchymal stem cells culture.

Key words: bone marrow-derived mesenchymal stem cells, serum, expansion