1. The process of dehydrogenation by chloranil has been studied in a series of saturated and unsaturated polymers, cis and trans polybutadienes and polyisoprenes, poly-p-chlorostyrene, polystyrene, polypropylene, polyethylene, etc. The overall activation energy of the process is 13–18 kcal/mole for diene polymers, 17–20 kcal/mole for polystyrene, and 27–28 kcal/mole for polyethylene and polypropylene. 2. When tetrachloro-o-quinone is used as dehydrogenating agent, the activation energy is decreased to 8 kcal/mole for diene polymers and to 11–13 kcal/mole for-polystyrenes. The diene polymers are dehydrogenated at a significant rate at temperatures of 30–40°. 3. In the cases of the atactic and isotactic polystyrenes and in the cis and trans diene polymers as well, the role of steric factors in the kinetics of the reaction was demonstrated. 4. Quantitative dehydrogenation of various polymers and copolymers with an excess of chloranil leads to the formation of poly conjugated materials and may serve as a method for the synthesis of polyacetylene and its derivatives.