Chosen Hanyin County of Shaanxi Province as the study area，this research intended to assess the quantitative methods of farmland productivity evaluation． On the basis of field investigations，sampling and chemical analysis，the automatic and quantitative evaluation procedure was realized by adopting the modified grey relation model，which was improved with incorporation of analytics hierarchy process and fuzzy math． The proposed evaluation method is of positive significance in scientifically managing and utilizing the cultivated land resources in China． The results show that farmland productivity in the study area could be classified into five grades，with grade Ⅰ accounting for 7． 32% of the total area，grade Ⅱ for 15． 41%，grade Ⅲ for 21． 61%，grade Ⅳ for 32． 47%，and grade Ⅴ for 32． 47%，respectively． The results also indicate that the farmland productivity in the study area ranged from inferior to intermediate; the farmlands of the river valleys have relatively high productivity，the farmlands of the rolling-hill areas have low productivity，and the farmlands of mountainous areas have the lowest．