In recent years, with the development of technology of component, component-based development (CBD) as a useful reuse methodology has been greatly paid attention and improved. The design and implementation of multilingual components library is a very important direction of the application and use of Multilingual (Arabic, Russian, etc.) software baseplatform. Component description model and componet description language is a cornerstone and major research direction for CBD. A reasonable and appropriate description of component will contribute to an effective represent, development, understanding, modification of reusable component. This paper will focus on how to design a rational and effective component description specification. First of all, we expatiate on the problem of component model, description method, description language from the point of methodology, and meanwhile introduce the popular component model and modeling language like Jade-Bird model, Specification of business component,WSDL. Then, considering the initial stage of the development of multilingual component library and its capability to support CBD, we propose an extensible component model based on the Jade-Bird Component and the specification of business component. In this model we depict the interaction of components from a view of process as complementarities of Object-Oriented interaction model; expand the context of component service with a newly defined expression; design a component quality model based on reuse. Our model implements the requirement of 3C. And finally, we design a component description language based on the XML Schema-xCDL, we focus on the complex matters such as: interfaces, service, facets dictionary, component space and component quality. our language system can be easily expanded for the future require. So we make a solid foundation for the composition of components.