Legume crops especially lentil is among the most important food groups due to their high nutritional value and due to their economic importance among winter crops. The cultivated area of ​​it may compete with the areas of competing crops in the same agricultural cycle, and the expansion of its cultivation is related to the nature and quality of the economic and productive variables. The research problem was represented in the local production deficit of the lentil crop as a result of the decrease in the cultivated area of ​​it, and then the increase in the deficit in the balance of payments. The aim of the research to study the most important factors that affect farmers' decisions and their response to cultivating lentil. The most important results that the cultivated area of ​​the lentil crop is decreasing annually by a statistically amount about 183.3feddans during the period (2001-2020). From the results of the response supply function, it was found that there is an economically logical inverse relationship between the cultivated area of ​​lentil in the current year and the agricultural price of lentil, the agricultural price of, the agricultural price of alfalfa crop, the price of beet, the price of chickpea, the price of flaxseed and the price of the garlic crop. This means that a decrease in the agricultural price of the previous variables by one pound leads to an increase in the area currently planted with lentil about 2.129, 1.005, 1.117, 1.9, 2.1, 1.98, 5.2 feddans, respectively.