FePtAg-C nanogranular perpendicular magnetic thin films with a mean particle diameter of 6.1 nm and coercivity of 37kOe has been developed for thermally assisted magnetic recording (TAMR). Using a TAMR static tester, a recording density of 450 Gbit/in2 has been demonstrated. This recording density is the highest for the TAMR recording, and is comparable to the highest recording density in current hard disk drives.