Abstract: Application of Manufacturing Execution System in the third assembly factory of First Tractor Co.，Ltd.Integrated management that included production management，technology，quality assurance，assembly trace back and other links was realized through information transmission. Match problem between advanced equipment and production management mode was solved through implementation of Manufacturing Execution System.It enhanced production management level，efficiency of management and decision speed of enterprise.At the same time，application of Manufacturing Execution System also improved quality of product and staff.