Abstract: Taking Huiyang City in Guangdong Province as an example for agricultural land gradation, factor method was compared with modifying method, and the process of gradation, the characteristics and scope of applications, and the rationality of the results of those two gradation methods were discussed. By the analysis of the space distinction(difference), space superposition (sameness), the incomes from different gradations and the correlation of classification, gradation and evaluation, the feasibilities of factor method and modifying method were studied. The gradation result of modifying method is in good agreement with the local practical conditions.