关键词: 策略生成, 多层策略表示, 分层网络系统模型, 策略属性, BNF范式

Abstract: Policy establishment and representation is the base of the policy research.Nowadays，device and technology oriented policy making excessively depends on the knowledge and the experiences，but ignores the requirement and the effect of the application environment.So the policy making is no integrity and liable to make a mistake.To solve the problem，hierarchy network security system model is designed，and the policy making and representation is proposed based on the system modeling，which make the policy making is not limited by the single device and the only one security function.Upon the method，the policy auto making is implemented to some degree and the correctness and the integrity are insured，which decrease the burden of the manager，and the possibilities of the mistaking.According to the refinement of the policy basic attributes，Multi-level policy representation method based on requirement-driven network system model is promoted.Using the BNF normal form to describe the policy grammar specification，policy representation is friendlier and more operable.

Key words: policy generation, multi-level policy representation, hierarchy network system model, policy attribute, Backus-Naur Form（BNF）