Poly(butadiene-alt-1-olefin) copolymers and poly[(butadiene-alt-ethene)-co-(butadiene-alt-1-olefin)] terpolymers, and the hydrogenated products too, has been characterized with the aid of differential scanning calorimetry (DSC). Both the glass transition and the melting behaviour of the partial crystallized products has been investigated. From the peak area the degree of crystalunity has been calculated in a first approximation. The results allow to draw conclusions about the crystallization behaviour in relation to the number and length of the side chains and about the course of the synthesis in question.