关联式规则(Association Rules, AR)，又称关联规则，是数据挖掘的一个重要课题，用于从大量数据中挖掘出有价值的数据项之间的相关关系。关联规则解决的常见问题如：“如果一个消费者购买了产品A，那幺他有多大机会购买产品B?”以及“如果他购买了产品C和D，那幺他还将购买什幺产品？”正如大多数数据挖掘技术一样，关联规则的任务在于减少潜在的大量杂乱无章的数据，使之成为少量的易于观察理解的静态资料。关联式规则多不考虑项目的次序，而仅考虑其组合。

关联规则一个经典的实例是购物篮分析(Market Basket Analysis)。超市对顾客的购买记录数据库进行关联规则挖掘，可以发现顾客的购买习惯，例如，购买产品X的同时也购买产品Y，于是，超市就可以调整货架的布局，比如将X产品和Y产品放在一起，增进销量。

Association rule learning is a method for discovering interesting relations between variables in large databases. It is intended to identify strong rules discovered in databases using some measures of interestingness. Based on the concept of strong rules, Rakesh Agrawal et al. introduced association rules for discovering regularities between products in large-scale transaction data recorded by point-of-sale (POS) systems in supermarkets. For example, the rule found in the sales data of a supermarket would indicate that if a customer buys onions and potatoes together, they are likely to also buy hamburger meat. Such information can be used as the basis for decisions about marketing activities such as, e.g., promotional pricing or product placements. In addition to the above example from market basket analysis association rules are employed today in many application areas including Web usage mining, intrusion detection, Continuous production, and bioinformatics. In contrast with sequence mining, association rule learning typically does not consider the order of items either within a transaction or across transactions.