Considering revenue business , we calculate support threshold of itemset and confidence threshold of rule , realize application and prediction by association rule mining in the audit department of tax system . by algorithms we analyse various illegal possibility , find out some implicit regulation among of factors , and guide current revenue work in audit 联系税收业务,从对项集的支持度、规则的支持度和置信度的计算入手,实现了关联规则算法在税务稽查部门的应用预测,通过算法分析各类违章违法的可能性,找出各种因素之间隐含的规律,从而指导当前税收稽查实际工作。