A multifunctional nanodrug system containing Fe3O4, o-carboxymethyl chitosan (OCMCs), and curcumin (Cur) has been prepared and characterized by infrared and fluorescence spectroscopy, X-ray diffraction (XRD), and field-emission scanning electron microscopy (FE-SEM). The fluorescent staining experiments showed that this system not only had no effect on the cell internalization ability of curcumin but also successfully led curcumin into the HT29 cells as expected. From real-time cell analysis (RTCA), the effect of Fe3O4/OCMCs/Cur on this cancer cell line was found to be much stronger than that of pure curcumin. This system contained magnetic particles and, therefore, could be also considered for hyperthermia therapy in cancer treatment.