Objective: The expansion of wet chemical method for the synthesis of iron oxide nanoparticles with magnetic properties is reported. Methods: Iron oxide nanoparticles were investigated in the procedure using Transmission Electron Microscopy (TEM). It has been seen that the distribution size changed by changing of Molarity precursor and heating the sample. The magnetization evaluations were performed using a Vibrating Sample Magnetometer device (VSM) to specify the magnetic answer. The Thermo Gravimetric Analyses (TGA) displayed the size-dependent weight loss of the magnetic nanoparticles. In this work, the cytotoxic activity of various samples of Maghemite on cancer cell lines HELA was studied. The in vitro cytotoxicity tests were also performed to determine the cell viability as a work of size and heat of the magnetic nanoparticles. Results: The samples c and d at T=300°C had a little magnetic hysteresis that can use in cancer cure with hyperthermia therapy method. Conclusions: These samples became amorphous and they were nontoxicity.