Information System Planning (ISP) plays an important role in IT strategy. ISP not only faces complicated and dynamic business environment but also lacks of integrated optimization of enterprise strategy, business strategy and IT strategy. This paper proposes an information system planning model, which considers enterprise forming strategic advantages as the core，and emphasizes that strategy layer should adapt to competitive environment dynamically in strategic whole life cycle, and emphasizes that collaborative interaction inside strategy layer should be achieved among enterprise strategy, business strategy and IT strategy. On this basis, make use of this model to plan agile information system of an automobile manufacturing enterprise and achieve important application effects
