The strategic ultimate aim of the dynamic balance maintenance of total farmland is to ensure the safety of food supplies and to make the output capacity of reserved farmland and the per capita output level increase.Because of the difference in occupied and supplement ed farmland quality,while the system quantity of farmland is monitored,we should warn the spatial-temporal range and dangerous degree of the quality degradation critical value.Therefore we can reflect the state of farmland system on the whole.The monitoring of farmland quality should be inte grated with the dynamic change of farmland area of all grades.The researches on the grading and ranks of farmland,the dynamic change of farmland quality and the monitoring system of dy-namic balance maintenance of total farmland should have unified index system and technological project,so we can solve the operational problem of"occupying one but supplying some "in ba-lancing occupation and supplementation of farmland quality.On the basis of the fixed-site moni-toring of occupied and supplemented farmland and farmland productivity grade based on the in-dex of farmland productivity,we have carried out the critical alertness and early warning of dy-namic balance maintenance of the total farmland,regarded that actualizing the strategy of dy-namic balance maintenance of the total farmland should be combined with the construction of farmland quality,the protection of basic farmland,technical advancement and population control-ling.