In this paper, we will improve "Kahn's method of idea forming" modeled based on Louis I. Kahn's designing philosophy as a design idea and design tool, aiming at practical use at the design site. And, it's the purpose of this study to do design experiment using the "improvement type Kahn's method of idea forming" way targeted for the professional designers and make the difference in the design trend with skilled professional designers and immature architectural student clear through the analysis.