To explore the correlation between the cellular inhibitors of apoptosis proteins (cIAPs) and the apoptosis of myelodysplastic syndrome (MDS) cell line (RAEB type) cells induced by aclacinomycin (ACM), the apoptosis of MDS cell line MUTZ-1 cells induced by ACM was analyzed with terminal deoxyribonucleotidy transferase mediated dUTP-biotin nick end labeling (TUNEL) technique. By using semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR), the expression levels of cIAP-1 and cIAP-2 mRNA in MUTZ-1 cells were assayed. The results showed as follow: (1) Using 0.5 micromol/L, 1.0 micromol/L ACM treated cells for 24 hours, the relative expression level of cIAP-1 mRNA (cIAP-1/GAPDH) was lower than those in the untreated cell group (P=0.002, 0.0002, respectively). (2) Using 0.5 micromol/L ACM treated for 6, 12, 24 hours, the relative expression level of cIAP-1 mRNA was 0.95 +/- 0.04, 0.73 +/- 0.05, 0.38 +/- 0.07, respectively and the relative expression level of cIAP-1 mRNA was correlated negatively with the time treated by ACM (r=-0.996, P <0.01). (3) Using 0.5 micromol/L ACM treated for 3, 6, 12, 24 hours, the relative expression level of cIAP-2 mRNA was 1.17 +/- 0.06, 0.91 +/- 0.03, 0.69 +/- 0.07 and 0.00 +/- 0.00, respectively and relative expression level of CIAP-2 mRNA was correlated negatively with the time treated by ACM (r=-0.091, P <0.01). (4) The percentages of TUNEL positive cells were correlated negatively with the relative expression level of CIAP1 and CIAP2 mRNA (r=-0.984, -0.959 and P=0.002, 0.013 respectively) when treated with increasing concentration of ACM. In conclusion, ACM can induce significantly MUTZ-1 cell apoptosis via suppressing expression of anti-apoptotic gene cIAP-1 and cIAP-2 mRNA.