Abstract: Objective To investigate the effect of DAB2IP gene on bladder cancer (BCa) cells response to ionizing radiation or antineoplastic drugs.  Methods The small interfering RNA (siRNA) system was implemented to inhibit endogenous DAB2IP expression in two human BCa cell lines, T24 and 5637. Cell radio-sensitivity and chemo-sensitivity were measured by a colony formation assay (CFA) and MTT assay , respectively. Results DAB2IP gene silencing caused cells tolerance to both irradiation and anticancer drugs. Conclusion DAB2IP may be used as a molecular marker to predict the prognosis of radiotherapy or chemotherapy on bladder cancer patients.