Structure and properties of poly(vinyl alcohol) (PVA) /borax complexes formed in the presence of gelatin at different pH, temperature and concentration of PVA and borax were investigated by measuring their crystallinity and solubilities. Infrared spectra indicated that the crystal region of PVA in the PVA/borax complexes changed into amorphous one, X-ray measurements of PVA/borax complexes formed in the presence of gelatin indicated that the crystallinity of PVA in those complexes decreased as the concentration of PVA. and borax and pH value increased. Thermogravimetric analysis showed that thermal stability of PVA/borax was consistent with X-ray measurements. The solubillities of complexes were dependent on the temperature and pH value.