It is an important modern trend to try to modify the surface properties of titanium implants with titanium oxide produced in various ways. One possibility of surface modification is the formation of an oxide layer by heat and electric treatment. The authors examined three osteosynthesis plates treated with anodic oxidation of Hungarian development. 5-10 microm thick slides were made of the plates in several cross sectional planes with a special cutting-grinding technique and were examined under a microscope with various magnifications. In the study it was seen that the surface of the basic metal was covered with a continuous oxide layer in all the cross sectional planes. No material faults were discovered on the surface. The thickness of the surface layer in various regions was found to be changing in the nm range, which coincides with the results of other studies. It was proven in the study by using the surface modification technique in part developed by the authors a passivating layer was formed on the surface of titanium, which separates it from the human organism.