In this paper photolysis mechanisms of polyketones polymeric materials are discussed in general. Photolysis machanisms of polyketones with carbonyl in main chain
such as CO/ E
CO/P
Co/St
random and alternating copolymers from carbon monoxide and olefins are discussed with emphasis. Norrish type I and Ⅱ reactions always take place in photodegradation
but Norrish type Ⅱ reaction does not occur for polyketones without γ - H.