First principle calculations have been performed to study the electron structures and magnetic properties of transition metal doped rutiles in order to predict room temperature diluted magnetic semiconductors. Different doping configurations have been calculated to find the preferred doping site. The ground state energies of both FM and AFM states have been calculated to study the magnetic coupling between the dopants. The calculation results show the Co doped rutile has a Curie temperature of 1438 K. Co doped rutile films have been prepared on Si substrate by magnetron sputtering. X-ray dif fraction results show that the deposited film is rutile. Hysteresis loop curves measured by vibration sample magnetization show that the film is ferromagnetic at root temperature.