The similarity transformation is introduced which reduce the hamiltonian and the dynamical matrix of the two-dimensional quasicrystals with A/-fold rotational symmetry. For the degeneracy, when N is even number, N-2 out of N+2 of electronic and phonon states are doubly degenerate and 4 out of N+ 2 are non-degenerate, and as N is odd number, N-1 out of N+1 of electronic and phonon states are doubly degenerate and 2 out of N+1 are nondegene-rate. We use group theory +o study the degeneracies of twodimensional quasicrystals and obtain the same conclusion.