Abstract: As the development of network technology, the runtime environment of software is becoming more and more complicated and the rectuirements of software users are growing with diversification. These variations lead to more advanced demands on the ability of dynamic evolution of software. The concept, which is called separation of concerns,during the development of aspect oriented software development, can well support the dynamic evolution of software.The existing formal methods can not represent the dynamicity of software architecture intuitively; however, more important is that they can not efficiently verify the validity of the system before and after the evolution. 13igraph not only has the ability of intuitive graphical representation, but also possesses better mathematical foundation. Therefore, we proposed a new model,which is called Aspect Oriented Dynamic Software Architecture(AODSA)，w solve these problems. First, l3igraph was extended in order to describe the structure of AODSA. Then, Bigraph reactive system(BSR) was used to represent the dynamic evolution of AODSA. At last, a simpleA),M deposit system model was used for example to illustrate the usage of AODSA.

Key words: Bigraph, Bigraph reactive system, AODSA, Dynamic evolution