  In the present paper, we study the continuous-time quantum walk on quotient
graphs. On such graphs, there is a straightforward reduction of problem to a
subspace that can be considerably smaller than the original one. Along the
lines of reductions, by using the idea of calculation of the probability
amplitudes for continuous-time quantum walk in terms of the spectral
distribution associated with the adjacency matrix of graphs [Jafarizadeh and
Salimi (Ann. Phys 322(2007))], we show the continuous-time quantum walk on
original graph $\Gamma$ induces a continuous-time quantum walk on quotient
graph $\Gamma_H$. Finally, for example we investigate continuous-time quantum
walk on some quotient Cayley graphs.
