This paper presents an algorithm on topic mining in BBS. As most articles in BBS are discussing rather than narrating something, it may be doubted that those articles on certain topic seem to be similar through vector space model. What's more, we may believe that those algorithms based on vector space model can't accomplish the task of hot topic mining effectively. In this paper, we first carry on a traditional clustering process. Second, according to the degree of hotness, we use accessing count, replying ...