Objective To provide data for reference on the impact of cyclosporin A (CsA) on the proliferation of the bone marrow mesenchymal stem cells in MDS patients through the investigation of the impact of cyclosporin A on human bone marrow mesenchymal stem cell proliferation. Methods The absorption rates of the bone marrow mesenchymal stem cells in the control group and the MDS patient group were determined by using the tetrazolinm salt (MTT) micro-colorimetric enzyme reaction. The concentrations of cyclosporine A are 2.5×10~4 ng/μl, 2.5×10~3 ng/μl, 2.5×10~2 ng/μl and 2.5×10ng/μl respectively. Results There is no significant difference between the each result by using different concentrations of CsA., which indicates the impact of CsA on the growth of mesenchymal stem cells is not significant(P >0.05). In the serial of concentrations mentioned, no cytotoxicity of CsA is observed. However, there is difference between the selected indicators of the control group and the patient group (P <0.01), and the value of the MDS patient group is higher than that of the control group. There is no statistic difference between the concentration of CsA and the data obtained from interactions between different groups (P >0.05). There is no significant difference between the absorption rates of the group treated by CsA of every concentration and the corresponding control group. Conclusion The impact of CsA on the bone marrow mesenchymal stem cell proliferation is significant in neither healthy people nor MDS patients.