The article generalizes theoretical aspects of mortgage lending in the agrarian sector of the economy. The key indicators of the mortgage market situation are determined. The factors hindering the development of mortgage lending to domestic agricultural producers are formulated and grounded. World experience in mortgage lending development is generalized. Two types of mortgage lending systems are considered, in particular one-level (European) and two-level (American) systems of functioning of the mortgage lending market are schematically presented. A meaningful comparison of these systems was carried out and their differences were formulated on the basis of a detailed study of the mechanism of refinancing of issued mortgages. The main sources of mortgage lending in agriculture are highlighted. The principles of foreign and domestic mortgage lending systems, which should be used to form an effective system of investment-mortgage agricultural lending in modern economic conditions, are singled out.