50-60 percent of patients who are diagnosed as myelodysplastic syndrome (MDS) are detected chromosomal abnormalities. Nowadays, G-banding is used to analyse karyotypes because of low cost and capability to detect a large number of complex chromosomal abnormalities. At Blood Transfusion and Hematology Hospital, from 1/2012 to 12/2013, 31/35 MDS cases which were cultured successfully (88.6 percent) showed that 12 cases were normal karyotypes and 19 cases had abnormal karyotypes. Of those 19 cases, 7 cases had single abnormalities, 8 cases had more double abnormalities and 4 cases appeared neartriploidy. These results helped medical doctors selecting suitable regimen for treatment.