The present invention relates to a shock-absorbent structure of serially-connected fans. The serially-connected fans at least include two fan frames. A shock-absorbent element is disposed between the bonded surfaces of the fan frames and is made of a flexible material being shock-absorbent and damping. Therefore, when the fan rotor inside the fan frame rotates, the fundamental frequencies of two fan rotors are damped, and absorbed by the shock-absorbent element, thereby preventing the interaction of the fundamental frequencies from generating severe resonant effect and noise out of vibration and maintaining the optimized efficacy and the life span of the system.