A systematic study of the symmetries of Liouville's equation for r-1-p
otential is presented. The canonical transformations in phase space wh
ich leave the hamiltonian invariant turn out to be the full symmetry t
ransformations of Liouville's operator, as well. The symmetry group is
SO(4). A maximal set of mutually commuting operators, and subsequentl
y, a classification of the eigensolutions of Liouville operator is pro
posed. The Kustaanheimo-Stiefel transformation is used to show that th
is SO(4) is isomorphic to a constrained SU(4) and contains all symmetr
ies of Liouville's equation for r-1-potential.