Both Al-Zn alloy and Mg-Al-Zn alloy are considered as high damping and light materials. This study investigated the effects of the structure and the composition on the vibration fracture characteristics of the Al-xZn alloy and the Mg-xAl-Zn alloy under resonance. For Al-xZn (x = 7, 11, 49, and 83 wt.%) alloys, under both constant force and initial-deflection conditions, the 7Zn specimen showed the greatest vibration life. For Mg-xAl-Zn (x = 3, 6, and 9 wt.%) alloys, experimental results indicate that the AZ31-F as-extruded samples showed a greater vibration life, while high A1 fully annealed samples (AZ91-O) had greater vibration fracture resistance under constant force conditions.