Elastic/acoustic metamaterials hold many exceptional mechanical properties， and provide a new way for the vibration and noise reduction of equipment in aerospace engineering and ship engineering. This paper presents an experimental study on vibration attenuations via a multi-cell and locally-resonant metamaterial. First， the paper discusses the wave propagations of metamaterials inside and outside the bandgap by means of the dispersion analysis， the wave transmissibility analysis， as well as the numerical computations on the vibrations of a periodic metamaterial. Second， the paper introduces a lightweight configuration of periodic locally-resonant metamaterial with bandgaps at the low frequency range. The experimental results show that the vibration transmissibility decreases by 30 dB in the frequency range of 15—45 Hz， exhibiting a good performance of vibration attenuation connecting space truss structure.