In this paper, the optical Bloch equations of a two-level atom ensemble driven by squeezed light field are derived. Based on these equations, we calculate the atomic absorption and dispersion. The results show that for different squeezing conditions of the field fluctuations, atomic absorption-lineshape exhibits sub-or super-natural linewidth phenomenon. Atomic dispersion depends on the squeezing direction and coherent excitation direction of the driving field. When these two directions are not parallel or perpendicular to each other, the dispersion zero-point shows a shift to the transition frequency of the atom.