Abstract: The quality of cultivated land reflects the level of regional agricultural production，and is also the demarcating foundation of basic farmland protection zone. Taking the Ili River valley qapqal xibe autonomous county as the study area，four indicators including land natural quality，cultivated land use condition，land space form and ecological security pattern were selected，the exponential decay assignment，multi－factor comprehensive evaluation and multi－factor index method were used to build the county farmland quality comprehensive evaluation index system，and combined with quality evaluation grade of each indicator， the preliminary plan of basic farmland protection zone in the county was determined. The results showed that the quality of cultivated land in the county was good and more than 50% was better，44.99% of the cultivated land was demarcated as primary farmland protection zone.