Fe 3 O 4 nanoparticles are synthesized by modified sol-gel method. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM) are used to characterize the manufactured product. Depending on the varying calcinations temperature the Fe 3 O 4 powder exhibits increased particle size in the range of 16-25nm. The designated results strongly influenced the microstructure, particle diameter and also the Electrical properties.