  The rare Bc->Ds l^+ l^- decay is investigated by using the most general model
independent effective Hamiltonian. The general expressions of longitudinal,
normal and transversal polarization asymmetries for l^- and l^+ and the
combined asymmetries of them are found. The dependencies of the branching
ratios and polarizations on the new Wilson coefficients are presented. The
analysis shows that the branching ratios and the lepton polarization
asymmetries are very sensitive to the scalar and tensor type interactions.
These results will be very useful in searching new physics beyond the standard
model.
