Service-oriented computing, which offers more flexible means for application development, is gaining popularity. Service-oriented grid applications are constructed by selecting and composing appropriate services. They are one kind of promising applications in grid environments. However, the dynamism and autonomy of environments make the issues of dynamically adapting a service-oriented grid application urgent. This paper brings forward a model that supports not only monitoring applications through gathering and managing state and structure metadata of service-oriented grid applications, but also dynamic application adjustment by changing the metadata. Besides that, the realization and application of the model is presented also.