In this article, we reported the hybrid copolymerization of ethylene and cyclic ketene acetals (CKAs) mediated by dithiocarbamate, in which the propagating radicals could open the rings of CKAs to incorporate cleavable ester units into the polyethylene backbone. The molecular weights and ester incorporation in the produced copolymers could be easily regulated. Furthermore, lipase could degrade the ester-containing polyethylene (PE)-based copolymers into short fragments effectively.