Abstract: As the blueprint for software development, software architecture（SA） is very important, and much more attention has been paid to the research on SA Architecture description language （ADL） is one of the keys to SA research An XML based ADL, named ABC/ADL, is presented in this paper ABC/ADL has the ability of describing the high level structure of software system Besides, it supports refinement, evolution, automated composition and verification of the system ABC/ADL adopts XML, the data inter operation standard, as its meta language This enables it to have inter operability with other ADLs as well as traceability between design phase artifacts and other software life cycle phase artifacts