Undrawn and drawn PVA films prepared by solution casting were iodinated with aqueous solutions of 0.1, 0.3, 0.5, 1.0, 2.0 mol/l of 12/KI and deiodinated by mixture aqueous solution of 7 wt% sodium thiosulfate and 5 wt% ethylene glycol. The fine structure of the films after deiodination was investigated by density, X-ray diffraction analysis, differential scanning calorimetry(DSC), and hire fringence determination. It was confirmed by the analyses of X-ray diffraction and DSC that the crystalline structure was recovered to the original PVA crystalline structure by deiodination. The degree of crystallinity was greater but the mean crystallite size of the film after deiodination was smaller than those of the untreated film. The melting points after iodination and deiodination were lower for the unoriented films and higher for the oriented films compared with those of the untreated film. The hire-fringence and amorphous orientation of the oriented film after deiodination were smaller than those of untreated film.