The principal storage reserve of sugar beet seeds is starch, which is localised in the perisperm. Additional storage reserves include the seed proteins, albumins, globulins and glutclins, which are exclusively located in the embryo. Soluble sugars are also detectable in all the organs of the mature seed. The time‐course of reserve mobilisation in the different organs of the sugar beet (Beta vulgaris L. cv. Regina) seed during germination and early seedling growth is documented, with particular reference to changes in (a) activities of hydrolases: a‐amylase, β‐amylase, and α‐glucosidases; (b) levels of carbohydrates and (c) proteins. Amylase activities increase substantially in both cotyledons, as well as the perisperm, whereas the increase in α‐glucosidase activities is largely confined to the perisperm.