As the data of the road transportation management information system are mostly inconsistent,impreciseand incomplete,a novel data mining method,which combines the rough set analysis with the classical associationrule,is proposed based on the system induction idea and the attribute reduction method of the rough set theory.Then,the relationship among the rule number,the support degree and the confidence is analyzed by using therough set method,and the reliability and validity of the proposed method is verified through a case study.The re-sults indicate that the proposed method can realize an attribute reduction of 33.3%,which means that the methodis effective in solving the problems existing in the real road transportation management system.