With the expanding of software scale and the intricacy of its structure,a higher demand on the code securityis required. As a new programming methodology, AOP provides a new approach forsecuringprogram design. Using this approach, the secure codescan be abstracted as an individualmoduleand the secure policy can be applied freely, and then, the secure codes take effect to core concern by weaving. Thus the reusebility and security of a program will beenhanced. The main idea of AOP is introduced and the design approach of AOP-based secure program is discussed. At last, an example is illustrated.