We　study　the　influence　of　screening　effect　on　quantum　decoherence　for　charge　qubit　and　the　process　of　quantum　information　storage.　When　the　flux　produced　by　the　circulating　current　in　SQUID　loop　is　considered,　screening　effect　is　formally　characterized　by　a　LC　resonator.　Using　large-detuning　condition　and　Frohlich　transformation　in　the　qubit-cavity-resonator　system,　we　calculate　the　decoherence　factor　for　charge　qubit　and　the　effective　qubit-cavity　Hamiltonian.　The　decoherence　factor　owns　a　factorized　structure,　it　shows　that　screening　effect　is　a　resource　of　decoherence　for　charge　qubit.　The　effective　Hamiltonian　shows　that　the　screening　effect　results　in　a　frequency　shift　for　charge　qubit　and　a　modified　qubit-cavity　coupling　constant　induced　by　a　LC　resonator.