With the social and economic development,the contradictions of arable land decline and non-agricultural construction area growing have become increasingly prominent.To solve the food security at the period of population peak,the state raised an important means of protecting arable land through the overall plan implementation.This paper concerns the problems of land tenure scale that exists in the overall planning of land tenure and suggests the new model.Next,it proposes the compute model of the arable total demand potential.Finally,determine the score the tenured arable land productive potential,combined the last year's score the tenured arable land productive potential,every year's changes of supply score of arable land productive and every year's changes of the score of arable land productive demanded.