Objective To study the changes of gene expression profile in K562 cells which were treated by RNA interference method targeting c-myc. Methods siRNAs were designed and functionally selected with RT-PCR and FACS. The siRNA targeting e-myc was indentificd and transfected the cultured K562 cells in vitro with lipofectamineTM 2000. The total RNA were extracted and reverse transcribed into cDNA,and hybridized to the K562 cDNA microarray after cy5- and cy3-1abeling. Results The hybridized microarray was scanned. The analysis for the data revealed that there were 455 down-regulated genes and 12 up-regulated genes. Conclusion RNAi coupled with microarray analysis may provide an efficient system to define the role of specific genes and a novel therapeutic tool for cancer.