1. Introduction
Association Rule is an important type of knowledge representation revealing implicit relationships among the items present in large number of transactions. Association rule mining (ARM) is firstly proposed by R.Agrawal, T.Imielinski and A.Swam in 1993[1]. The fast algorithm called Algorithm Apriori is put forward in 1994[2]. Much effort has been devoted and algorithms proposed for discovering association rules efficiently [3] [4]. These conventional association rules are widely used in many application domains, such as market basket analysis and web trace.