The crystallization behavior and the structure of the welded samples of the Ni53Nb20Ti10Zr8Co 6Cu3 glassy alloy are studied. A large supercooled liquid region of about 50 K observed enables its successful welding. On heating the supercooled liquid crystallizes by polymorphous mechanism forming a single metastable hR14 Ni4Ti3 phase which further transforms at higher temperature forming several equilibrium phases. Its composition was found to be very close (equal within the confidential interval) to that of the glassy phase. The kinetic analysis confirmed the interface-controlled polymorphous transformation mechanism observed. Good bonding between two glassy samples was obtained after welding. The results indicate that with an increase in the welding speed from 2 to 3 m/min the structure of the welded zone changes from the amorphous + hR14 Ni4Ti3 crystalline phase to an almost single amorphous one. By adjusting the welding speed one can obtain the desired microstructure. The samples electron-beam welded at the beam current of 4 mA and voltage of 60 kV at a speed of 4 m/min were found to be almost amorphous. The results indicate successful welding of the Ni-based glassy samples.