To realize usability of software, consistency of GUI (Graphical User Interface) layouts is required. Consistency is realized by user interface guidelines, in many cases. However, there are many items in the guidelines, and it is difficult to apply all items to GUIs in terms of costs and schedule. In our method, we have proposed a method to realize consistency of GUIs. Concretely, source programs of developed GUIs are analyzed, and layout rules are extracted. Then, source programs of undeveloped GUIs are generated based on the extracted layout rules.