The endosperm, a seed tissue that mediates the transfer of nutrients from the maternal parent to the embryo, is an important site of imprinting in flowering plants. In Arabidopsis thaliana, three genes were identified that prevent fertilization-independent seed development: FIS1/MEDEA, FIS2 and FIS3/FIE. MEDEA (MEA), a master regulator of endosperm development, is known to be imprinted in the endosperm. FWA is also imprinted in the endosperm of the model plant Arabidopsis. The following aspects were included in the present review: the imprinting mechanism in angiosperms, the latest progress in the control of MEA and FWA imprinting, the parental conflict theory to explain imprinting, the imprinting methods and other imprinted genes found in plants.