On the background of general county-level landuse planning,the study is conducted to coordinate the contradiction between farmland protection and construction development.Based on Lulong Countys general landuse planning reformulation in 2010-2020 and capacity theory,as combined with the outcome of agricultural classification and gradation,the county's productivity in 2020 is predicted to be 215 330.09 tons from the aspects of land development,consolidation and reclamation.Drain demand of the county in 2020 is predicted to be 21 000.10 tons using productivity and grain demand prediction methods and thus remaining grain productivity will be 4 329.99 tons under the precondition of regional food security.It is concluded that the county will have 768.07-1179.02 hmz farmland that may be used as newly increased construction land for industrialization and urbanization.Result from the study provides theory and methods for the prediction of newly increased construction land,reasonably and scientifically.