One dimensional tight binding model with electron-lattice interaction is adopted to study the effect of the density of itinerant electrons on the electronic structure of DNA and the charge transport in DNA. 我们采用包含了电子&晶格相互作用的一维紧束缚模型研究了巡游电子数密度对DNA分子的电子结构及其电荷输运性质的影响。