To select interesting rules from the set of all possible rules, constraints on various measures of significance and interest can be used. The best-known constraints are minimum thresholds on support and confidence. Association rule mining is an important field of knowledge discovery in database. Association Rule mining discovers uncover relationships among the hidden data in large databases. The Apriori algorithm is the classic algorithm in association rule mining. This paper compares the three Apriori algorithms based on the parameters as size of the database, efficiency, speed and memory requirement.