The capabilities of computer through the methodologies of scientific computing used to solve many manufacturing difficulties of semiconductor materials, across all disciplines, because it is low cost and the availability of resources. In this paper, investigation of unique electronic property of zinc oxide sheet, which can be an attractive semiconductor material for many electronic devices applications, is carried out. The electronic structure of zinc oxide surface and the effect of substituting lithium atoms using CRYSTAL06 code showed that the bulk ZnO band gap ≈ 3.3eV which is in good agreement with experimental results≈3.4eV. After generating slab structure, the band gap has been increased to 5.5eV, exhibiting high resistivity surface. Substituting of lithium to slab has decreased band gap to 4.4eV. The results shows that there is reduction in band-gap and decreases in resistivity, predicting that Small amount of Lithium could change the zinc oxide from wide band semiconductor to half-metal compound.