This study aims to present the differentiating factors of B2B salesperson competency through comparing the suppliers and buyers in Korean steel industry in their perception on the importance and priority of B2B salesperson competency. Based on previous studies, analysis on B2B salesperson competency has been analyzed using the B2B salesperson performance competency measure factors and appropriately reorganizing them for better application to the steel industry. The required performance competencies of B2B salesperson can be categorized into 3 different types, namely social exchange competency, advisory sales competency, and skill & knowledge competency. AHP analysis was performed for analyzing the relative importance of B2B salesperson competency based on the factors of previous studies, in which categorization of the aforementioned types had been done. As the result, first, it has been confirmed that there is a difference in 1st layer main factors between the supplier group and buyer group. The supplier group valued the advisory sales competency, while the buyer group valued skill & knowledge competency. Second, it has been proved that there is same result of relative importance in 2nd detailed factors between the supplier group and buyer group. Both group confirmed that customer member, identify customer needs and communication skill are very important factors. Third, as the result of analysis on the gap between B2B salesperson competency of the suppliers and buyers, the gap in the product knowledge and sales team member need improvement for buyer’s satisfaction according to overall results of relative importance and priority. The steel supplier was able to develop B2B salesperson competency according to the buyers’ needs based on the result of this study, and furthermore it is expected that this study will be able to contribute to increase in buyer competitiveness through differentiation in B2B salesperson competency.