This paper designed decision support system for mechanical conservation tillage, which includes three subsystems, such as subsystem of development potential estimation, subsystem of optimum model or suitable models selection, and subsystem of economy benefit estimation. In different area, it is necessary to alter, increase or decrease some evaluation index to accommodate the agricultural production. This decision support system is based on the ordinary technique such as .NET Framework and SQL Server 2005, which includes three kinds of function and four levels.