Reaction of resorcinol and 1,4-butanedial [(CH2)(2)(CHO)(2)] in the presence of concentrated HCl in ethanol at 80 degrees C for 48 h afforded a soluble polymer (CRA-polymer) in quantitative yield under thermodynamic control. Single X-ray crystal analysis revealed that the precursor product had cyclic structure, and TOF mass spectroscopy of CRA-polymer revealed a ladder structure with calixresorcinarene moieties in the main chain. The photoinduced deprotection reaction of CRA-polymer derivative (CRA-polymer-BOC) containing-tertbutyloxycarbonyl groups were examined in the film state in the presence of photoacid generator to produce the alkaline developable CRA-polymer with release of isobutylene and carbon dioxide.