User-centered philosophy is the trend of modern website design and its construction nowadays. In this paper, the methods of Kansei Engineering are imported to help improving the interact efficiency of an online Business-to-Business commercial website. First we collect the statistics result of up to 80 samples of user investigation, then the way of semantic differential has been used to reduce data dimension. The obtained representatively numerical knowledge makes it more effective for designer to carry interaction design in the prophase process. The website is redesigned accordingly. In later period, the skill of Kansei Engineering is still used to evaluate the effects of former design, new design and two competitors' website design. Experimental results show that the new design surpasses than others. And our proposed method could get more objective and more accurately of interaction than traditional experience-based design.