Abstract: The suitability evaluation for farm land by the gradual type convergence method needs a series of work.The evaluation factors should be chosen in acoordance with the growth needs of the crop,and the data for these factors should be corrected,quantified,and standardized.Only on this basis,type convergence analyses can be carried out.Proper types can,be sorted out through programming and computation,and classes for each type of land can be determined according to the location of the convergence center.

Key words: Gradual type convergence, Land suitability evaluation