Many efforts have been taken to achieve automated Graphical User Interface (GUI) testing. The most popular way is model-based testing, which supports automated test case generation and execution. But building such a model is a non-trivial task, which usually costs the most work-load in the entire testing process. Most of the approaches about automated model deriving are dependant on the programming language or specific OS. In this paper, we proposed a new approach of GUI modeling using Optical Character Recognition (OCR), and technical poblems encountered have been analyzed in deatail. Case study shows that our approach is capable of analyzing most of the GUI windows, and generating corresponding model and hence eliminates the above constraint.