Recent data established the prospective applications for fullerenol (C60(OH)24) nanoparticle (FNP) in many fields, such as antioxidants, neuroprotective agents, and potential anti-radiation drugs. Leukemia cell sensitization to apoptosis induced by ionizing radiation is achieved by upregulation of ROS production and/or downregulation of antioxidative enzymes. Therefore, our aim was to analyze the potential role of fullerenol nanoparticle in modulation of the leukemic cellular response to irradiation. We used the qRT-PCR to analyze the expression level of mRNA for 11 genes in irradiated and FNP pre-treated irradiated K562 cells, and compared the gene expression level with the overall cell survival. Our results of the improved cell survival in FNP-treated irradiated cells and significant overexpression of anti-apoptotic Bcl-2 and Bcl-xL and cytoprotective genes such as GSTA4, MnSOD, NOS, CAT and HO-1 genes, may indicate that FNP exerts cytoprotective function in K562 leukemic cells, rendering K562 cells more tolerant to radiotherapy.