Local production of lentil crop is not enough to face the local demand which is very increasing. The gap between production and demand is covered through importing from foreign countries which makes economic stress on the trade balance.  The changing of agricultural policies affect the production of lentil crop and also it production cost and profits. The objectives of this study are to shed lights and analyze the important factors affecting the lentil crop in Assiut governorate. The methodology adopted in this study is the descriptive approach to explain some results as well as the quantitative approach such as index numbers to assess the effect of policies on production cost and net return per feddan into three period, (1980-1986) as a basic period and (1987-1993), (1994-2010) as a comparison periods. In addition the study has also estimated models of supply response and elasticity for lentil crop in Assiut governorate during the period (1994-2010).  This study depends on the secondary data published and unpublished which are collected from different sources for the study period. Some economic studies related to this subject are considered.