Magnesium alloys are considered as a suitable candidate for implants due to their desirable properties such as non-toxicity and desirable mechanical properties. The functional limitation of these materials is their high corrosion rate in the physiological environment of the body. One of the methods that can significantly increase the corrosion resistance of these alloys is electrolytic plasma oxidation. In the present study, coating was performed in three different phases to investigate the effect of voltage, waveform and applied frequency in a phosphate-free bath containing 3 g / l of CaO particle additive on AZ31 alloy. Electron microscopy, X-ray diffraction phase detection and electrochemical corrosion tests were performed to investigate the microstructure, fuzzy composition and corrosion behavior of the coatings, respectively. Based on the electron microscopic images and the results of the polarization test, it was concluded that the increase in voltage has more favorable corrosion properties due to the creation of a structure with less defects and greater thickness. However, its excessive increase (ie, 450 volts) led to non-uniform coverage, especially in the form of bipolar waveforms. The applied wave deformation had a significant effect on the corrosion behavior, elemental chemical composition, morphology as well as the discharge behavior during coating. The coating formed in the bipolar waveform had cracks due to the intense release of hydrogen gas in the cathode cycle, which led to weaker barrier properties in these coatings. The presence of the cathode cycle led to the entry of more calcium-containing particles with positive zeta potential, resulting in a coating with higher bioactivity and smaller pore size. The presence of particulate additives had a negative effect on the barrier properties of the coatings in the short term due to the formation of a thinner coating and more cracks. However, due to the higher ability to form apatite and blockage of cavities in the very first moments of immersion, these coatings were able to show higher resistance to corrosive solution in the long run. As the cathode cycle increased in the bipolar waveform, high-intensity cathodic discharges formed on the coating surface, causing damage to the coating and cavities in the substrate. Frequency reduction due to thicker coating and more calcium particles led to better corrosion resistance and higher bioactivity. Keywords: Electrolytic Plasma Oxidation, Magnesium Alloy, Corrosion Resistance, Calcium Additive, Bioactivity