In order to use titanium in frictional pair with relative motion, titanium surfaces were modified by self-assembled method and the prepared samples were irradiated by ultraviolet radiation/ozone photochemical process. The characterization and tribological properties of samples were conducted by contact angle measuring meter, atomic force microscopy and microtribometer, and the hydroxylation of titanium surfaces by different methods was explored. The effects of load, sliding velocity and ultraviolet radiation on the tribological properties of samples were analyzed. The results show that the combining Piranha solution with ultraviolet radiation/ozone photochemical process can prove the effect of titanium surfaces hydroxylation. The titanium surface modified by FOTS SAMs is uniform and exhibits good hydrophobic and tribological properties. The friction coefficient between Si3N4 balls and sample surfaces modified by FOTS SAMs increases with load and sliding velocity increasing. The effect of modification treated by FOTS SAMs can be improved by an ultraviolet radiation/ozone photochemical process for 5 min. The durability of friction pairs is retained in the case of reduction of coefficient of friction for the modified titanium surfaces