For production of biosensor components and systems the wide range of metal materials is used. Among them magnesium alloys represent special interest. At the same time the most negative feature which significantly limits the abundance of the magnesium alloys is its low corrosion resistance. As a decision of the problem we propose the designing of composite material with a required speed of corrosion. It could be reached by means of micro-arc oxidizing – MAO (otherwise plasma electrolytic oxidation – PEO) of magnesium alloys surface.  Now the MAO method is more widely apply due to its possibilities to synthesis on magnesium alloys surface the high-adhesive nanoceramic layers which potentially capable to provide control of corrosion and protective ability [1]. Analysis of publications concerning this matter shows that for ignition of the micro-arc discharges on magnesium alloys and improvements of protective properties of MAO-coatings researchers use the complex electrolytes containing fluorides and phosphates. For example in [2-4] the attempts of insoluble protective film formation containing fluoric chemicals on magnesium alloys surface are described.   In this work the dependence of electrochemical corrosion rate (corrosion current density) of magnesium alloy MA2-1 samples with MAO-coatings (MAO-treatment: anodic-cathodic mode with frequency 50 Hz at equality of anodic and cathodic currents and their total density 11 A/dm²) on the concentrations of NaF and KF additives in basic silicate-alkaline electrolyte with the help of potentiodynamic polarization tests was investigated. Tests were carried out in 3 % NaCl solution with polarization rate of 1 mV/s using a three electrode cell setup. The obtained data are presented in the table. It can be seen that NaF (excepting 2 g/l) and KF (excepting 2 g/l) additives in basic MAO-electrolyte improves the corrosion resistance of magnesium alloy MA2-1.