During the storage of sunflower seeds with moisture content adjusted to 6 and 18%, activity (by the diffusion method) and immunoreactivity (by the immunoblotting method) of lipase were examined. The activity of sunflower lipase ranged from 28,4 to 37,5 A.U./mg protein and from 24,5 to 31,4 A.U./mg protein during storage of sunflower seeds with moisture content adjusted to 6% and 18%, respectively. Protein fraction characterized by molecular weights of 78 kD on electrophoregrams of protein extract from sunflower seeds with moisture content 6% cross reacted with the anti-lipase antibodies. The presence of immunoreactive proteins however was not detected in the extracts from sunflower seeds with 18% moisture content. The enzyme immunoreactive properties appear to be affected by moisture content to a higher extent as compared to its activity, so no relationship between the enzyme activity and immunoreactivity is observed.