The diode consisting of nano-silicon quantum dots embedded in an amorphous silicon matrix was fabricated and the discontinuous staircases on its I-V curves were observed.There were two distinct regimes on I-V curves of diode:(i) the sequential tunneling regime,where current increased monotonously with increasing negative bias;(ii) the resonant tunneling regime,where the current increased dramatically with increasing negative bias,and three quantum staircases appeared.It was found that the steps was related to the grains of the deposited film.The qualitative explanation of this physical phenomenon was proposed in terms of the material structural characteristics.