These notes were taken from lectures given by tom Dieck in the win- ter-term 1969/70 at the Mathematical Institute in Heidelberg. The aim of the lectures was to introduce the students to cobordism theory and to propagate ideas of Boardman and Quillen about the calculation of cobordism theories with the aid of formal groups. These notes give an enlarged version of the leetures with many details and proofs filled in. A chapter on unitary cobordism has...