  We report the preparation of Mg1-xLixB2 compounds. Nearly single phased
samples were obtained for x<0.3. The in-plane lattice parameter a decreases
with Li doping, while the lattice parameter c does not show obvious change. The
superconducting transition temperature of Mg1-xLixB2 decreases with Li doping
and loss of superconductivity occurs for x=0.5 sample. The results of our work
are consistent with the prediction of the hole superconductivity mechanism.
