Objective:To explore the relationship between the expression of glucosylceramide synthase(GCS) gene and multidrug resistance MDR in human leukemia. Methods:Using β-actin gene as internal reference, the level of GCS, mdr1, BCL-2 and BAX gene in 36 clinical multidrug resistance/non-resistance blood samples with acute leukemia were detected by RT-PCR technique. Results:The relative quantities of GCS and mdr1 genes in multidrug resistance group were significantly increased compared with non-resistance group(P < 0.001). The expression of BCL-2 gene in multidrug resistance samples was also significantly higher than that in non-resistance group(P < 0.001), but the expression of BAX gene was significantly lower in multidrug resistance group(P < 0.01). There was a significant difference in BCL-2/BAX ratio between multidrug resistance and non-resistance groups. Conclusion:The high expression of GCS gene is possibly correlated with multidrug resistance in acute leukymia, and cell apoptosis might be one of the main molecular pathology mechanisms of multidrug resistance caused by GCS gene.