Two oceanographic Radars targeting tsunamis had been installed in Wakayama Prefecture in Japan. To study obeservation capabilities of the radars on far field and near field tsunamis, numerical experiments were carried out. After starting the operation of the radars, nine earthquakes occurred in the observation area, however, they were too small to be observed by the radars. Parameter study on near field tsunamis showed the radars can observe earthquake of Mw 7 and very shallow Mw 6. As a far field tsunami, the 2012 Haida Gweii Earthquake Tsunami arrived at Japan, however, the radars could not detect it because of very small velocity. Parameter study on far field tusnamis showed the main energy of tsunamis off Canada propagates northward, and Oshika Peninsula is suitable to observe the tsunamis.