this thesis describes the photolysis of para-substituted styrene polymers. poly(vinylacetophenone), poly(p-bromostyrene), poly(p-chlorostyrene), poly(p-fluorostyrene), poly(p-isopropylstyrene), poly(p-methoxystyrene), and poly(p-tert-butylstyrene) films have been irradiated with short-wave ultraviolet radiation (wavelengths less than 300nm) under high vacuum at 25°c. poly(vinyl acetophenone) has also been irradiated with long-wave ultraviolet radiation (wavelengths greater than 300nm) under high vacuum at 25°c.