Hexamerins are proteins related to hemocyanins but they lack the ability to bind copper ions and transport oxygen. Hexamerin is the most abundant protein in honey bee (Apis mellifera) larvae and pupae. It is produced by larval fat body and serves mainly as a storage of amino acids but there is an evidence that it may act also as a juvenile hormone-binding protein. There are four types of hexamerin genes in honey bees, termed hex70a, hex70b, hex70c and hex110, which differ in the structure and expression patterns. The Hex70b is a methionine-rich hexamerin and it may serve as a sulphur reserve for development toward the adult stage . Here we present a crystal structure of honey bee Hex70b. Hex70b was purified from honey bee pupae and crystallized. The three-dimensional structure has been solved to 3.2 Å resolution using molecular replacement. The structure provides a basis for further studies of honey bee life cycle where participation of hexamerin is essential.