  We find a quantum group structure in two-dimensional motion of
nonrelativistic electrons in a uniform magnetic field on a torus. The
representation basis of the quantum algebra is composed of the quantum Hall
wavefunctions proposed by Haldane-Rezayi at the Landau-level filling factor
$\nu=1/m$ ($m$ odd). It is also shown that the quantum group symmetry is
relevant to the degenerate Landau states and the deformation parameter of the
quantum algebra is given by the filling factor.
