【摘要】分析了安全标记的概念，给出了安全标记的形式化定义，并建立了动态多级安全标记的格模型理论。格模型理论回答了动态多级安全系统的安全标记集合在数学上应形成格，解决了两安全标记比较时上、下确界的存在性问题，为多级安全性从静态安全政策，通过该策略的历史敏感性特征转化为动态安全政策奠定了理论基础。关 键 词 标记; 动态多级安全; BLP(Bell LaPadula)安全模型; 多安全政策; 格Conception of secure labels is analyzed, and defined by formalization, subsequently the lattice model theory of labels for dynamic multi-level security is established, which shows that the set of secure labels for dynamic multi-level security comes into being “lattice order” in math, and solves the existence of g.l.b and l.u.b when one secure label compares to other, and establishes the theoretical basis for change from static multi-level security to dynamic multi-level security according to the history sensitivity.