When　the　nonlinearity　of　nanomechanical　resonator　is　not　negligible,　the　quantum　decoherence　of　charge　qubit　is　studied　analytically.　Using　nonlinear　Jaynes-Cummings　model,　one　explores　the　possibility　of　being　quantum　data　bus　for　nonlinear　nanomechanical　resonator,　the　nonlinearity　destroys　the　dynamical　quantum　information-storage　and　maintains　the　revival　of　quantum　coherence　of　charge　qubit.　With　the　calculation　of　decoherence　factor,　we　demonstrate　the　influence　of　the　nonlinearity　of　nanomechanical　resonator　on　engineered　decoherence　of　charge　qubit.