Abstarct: This study examines the factors influencing farmland conversion, their impacts and the applicable regulations for the protection of agricultural land. Using a panel regression analysis, threshold regression method, and data from the Statistics Center of Iran, Jihad Ministry of Agriculture, and provincial land affairs and planning organizations, data were collected from 1390 to 1398 in 31 provinces of Iran. The first model considers variables such as value added, land, capital and labor for both the agricultural and non-agricultural sectors. The results of this model compare the economic interests of the two sectors in different provinces. Additionally, the study calculates the food security and job security values lost in the agricultural sector due to land use changes. The second model uses variables such as economic growth, agricultural land use changes (authorized and unauthorized), population, human capital investment, local intervention, provincial industrial structure, income differential, consumer price index, and foreign direct investment. The results of this model estimate the optimal amount of agricultural land use change constrained by economic growth for each province. This helps provinces that either exceed or fall below the optimal threshold to align agricultural land use change with economic growth. baxsed on the research results, it is recommended that government and regulatory authorities consider the economic interests and returns of agricultural land in different provinces and aim for optimal agricultural land use change in future policy making.