Ultrasonic for MoSi$_2$/Y. C. Kim, C. K. Namkoong/MoSi$_2$in the silicides has excellence in the oxidation and corrosion resistence. When the solid state bonding sintered-MoSi$_2$/metal or the thermal sprayed coating by powder-MoSi$_2$on the metal are carried out, the defects may be occured at the bonded surface. So, the method for evaluating the existence of the defects by non-destructive inspection is strongly desired. Here, the characteristics of ultrasonic for sintered-MoSi$_2$are elucidated and the possibility of the detection of defects using by ultrasonic is investigated.