Fabrication of Co-Pt and Fe-Pt ferromagnetic nanodot arrays for the application of ultra-high density bit patterned media (BPM) by electrochemical processes was described. In order to form patterned substrates for nanodot arrays with the density higher than 1 Tbit/inch2, electron beam lithography technique was employed. Nanopatterns with 25 nm and 18 nm pitch, which correspond to 1 and 2 Tbit/inch2 were successfully formed by optimizing the condition of the lithography process, and Co-Pt and Fe-Pt with relatively high coercivity of 4.8 kOe and 10.3 kOe were formed by electrodeposition. By utilizing the nanopatterned substrates, Co-Pt and Fe-Pt nanodot arrays with 25 nm and 35 nm pitch were uniformly formed. These results demonstrate capability of the electrochemical processes for fabricating magnetic nanodot arrays with Tbit-level density.