The purpose of our study was to investigate the role of VD3-IGFBP-3 induction system in cell growth inhibition and to propose the potency of low-dose VD3 usage which could evade side-effect of VD3 treatment such as hypercalcemia in therapy for patients with prostate cancer, thus 1 nM of DHT and 10 nM of VD3 concentrations were chosen as minimum but stably working concentration for following experiment. This evidence concerns the gene IGFBP3 and prostate cancer.