Abstract
As one has problems or decision issues, he/she always searches for the answers and the useful information on various social networks of Internet in order to acquire advices from the users with expertise. People depend highly on these users to provide some solutions or references for decision based on their own professional knowledge. On the other hand, manufacturers, advertiser or agencies always try to find the representative opinions of replies from the discussions in the online social networks, then they could identify the users who have leadership to endorse their products or service for increasing sales or visibility. However, people and vendors have to spend a lot of time sifting the useful informations from the user's replies. In order to solve the problems, this study develops a model for experts and leaders select of reply. It can be used to recommend experts and leaders. By applying the proposed model, people and advertisers can screen of experts or leaders and consult with experts or cooperation with the leaders very quickly.