We have synthesized novel photodegradable polyimides with sulfonyloxyimide units in the polymer main chain. The yield and molecular weight of polyimides were significantly influenced by polymerization condition and monomer structure. The prepared polyimides were stable up to 300 degreesC. The effects of polymer structure on photodegradable characteristics were examined. The photodegradation of polyimides upon irradiation with deep UV resulted from scission of N-O bonds or ling opening of imide moiety. The polyimides are useful as positive working photodegradable polymers. Especially, it has been found that the positive tone image of polyimide derived from pyromellitic dianhydride units has high sensitivity and resolution.