Land lease, contrary to land purchases, increases the mobility of land, which is the main factor of production in agriculture. In the EU countries the lease is a basic instrument increasing land mobility and leading to the increase in the area of farms, which in turn stimulates the transformation of the agrarian structure. In such countries as Belgium or France the leased land accounted for over 50% of the agricultural land in 1986. The relevant legal regulations in the EU countries are advantageous to stability and durability of farming on the leased land. Until 1990 the share of land under lease in Poland was less than 4%. However, the ownership and structural transformations in agriculture have caused the significant increase in land mobility through land leases only since 1990. The increase in land mobility leads to both the enlargement of the area of farms and the growth of the production volumes which enable farmers to generate income at a satisfactory level and to adjust their farms to the changeable market conditions.