Retinoic acid and its synthetic derivatives are considered as potential agents in cancer therapy because of its pharmacological effect to promote differentiation and to inhibit proliferation of cancer cells. However, clinical trials are greatly hindered by the side effect of retinoic acid with pharmacological dose and limited knowledge of retinoic acid functionalizing exerted on entire cells. Here, we applied atomic force microscopy as a less invasive approach to monitor the retinoic acid induced effect on entire live neuroblastoma cells. Our studies demonstrated that the live SH-SY5Y cells were stiffened and demonstrated the morphology of orientated growth. The Young's modulus and surface roughness of cells were increased under retinoic acid stimulus, which could serve as novel indicators for possibly development of anti-cancer drug screening.