In this research, cobalt ferrite nanoparticles were synthesized by the modified sol-gel method. Ethylene glycol was used as a gelling agent and sucrose to improve the particle size and prevent the product from self-assembly. The dry gel was calcined for 3 hours at 600, 700 and 800 °C. The products were characterized by TG-DSC, FT-IR, XRD, SEM, EDX and X-ray map. The size of nanoparticles was estimated to be about 30 nm using SEM images. The magnetic properties of the synthesized nanoparticles were also determined using a vibrating vibrational magnetometer (VSM), which revealed a saturated magnetization of 75 emu.g -1 for sample 5S. The nanoparticles was then coated by poly ethylene glycol as a bio-degradable and biocompatible polymer to use as a carrier for drug delivery. The antioxidant Doxorubicin drug was then coated on the surface of the nanoparticles, and its drug release from the substrate of coated nanoparticles containing doxorubicin was evaluated at different pH levels. To determine the amount of doxorubicin in phosphate buffer, UV-Vis spectroscopy was used. The results showed that the change of pH is effectire in the release rate of the drug from the nanoparticles and, the dosage of doxorubicin is increased, in an acidic pH.